Jayles, B., Kim, H. (金ヘリン), Escobedo, R., Cezerad, S., Blanchet, A., Kameda, T. (亀田達也), Sire, C., & Theraulaz, G. (2017). How social information can improve estimation accuracy in human groups. 社会情報は人間集団における推定の精度をどのように向上させ得るか Proceesings of the National Academy of Sciences of the United States of America, Early Edition (Nov. 8, 2017). doi: 10.1073/pnas.1703696114
In our digital and connected societies, the development of social networks, online shopping, and reputation systems raises the questions of how individuals use social information and how it affects their decisions. We report experiments performed in France and Japan, in which subjects could update their estimates after having received information from other subjects. We measure and model the impact of this social information at individual and collective scales. We observe and justify that, when individuals have little prior knowledge about a quantity, the distribution of the logarithm of their estimates is close to a Cauchy distribution. We find that social influence helps the group improve its properly defined collective accuracy. We quantify the improvement of the group estimation when additional controlled and reliable information is provided, unbeknownst to the subjects. We show that subjects’ sensitivity to social influence permits us to define five robust behavioral traits and increases with the difference between personal and group estimates. We then use our data to build and calibrate a model of collective estimation to analyze the impact on the group performance of the quantity and quality of information received by individuals. The model quantitatively reproduces the distributions of estimates and the improvement of collective performance and accuracy observed in our experiments. Finally, our model predicts that providing a moderate amount of incorrect information to individuals can counterbalance the human cognitive bias to systematically underestimate quantities and thereby improve collective performance.
Ozono, H.（大薗博記）, Kamijo, Y., & Shimizu, K. (2017). Punishing second-order free riders before first-order free riders: The effect of pool punishment priority on cooperation 1次のフリーライダーより先に2次のフリーライダーを罰するべし：プール罰の優先順位が協力に及ぼす効果 Scientific Reports, 7, 14379. doi:10.1038/s41598-017-13918-8
Second-order free riders, who do not owe punishment cost to first-order free riders in public goods games, lead to low cooperation. Previous studies suggest that for stable cooperation, it is critical to have a pool punishment system with second-order punishment, which gathers resources from group members and punishes second-order free riders as well as first-order free riders. In this study, we focus on the priority of punishment. We hypothesize that the pool punishment system that prioritizes second-order punishment is more likely to achieve cooperation than the system that prioritizes first-order punishment, because the former is more likely to obtain sufficient punishment resources. In the experiments, we compare four pool punishment systems: 1To2 (first-order punishment to second-order punishment), 2To1 (second-order punishment to first-order punishment), 1ONLY (first-order punishment only), and 2ONLY (second-order punishment only). We find that the 2To1 and 2ONLY systems can receive more support than the 1To2 and 1ONLY systems and only the 2To1 system can achieve high cooperation. However, the effect of priority of second-order punishment is observed only when the punishment ratio (PR) is low (Experiment 1), not high (Experiment 2), in which the punishment resource is relatively abundant.
Bjornsdottir, R. T., Tskhay, K. O., Ishii, K. (石井敬子), & Rule, N. O. (in press). Cultural differences in perceiving and processing emotions: A holistic approach to person perception. 感情の理解と処理における文化差：対人知覚の包括的なアプローチ Culture and Brain. doi: 10.1007/s40167-017-0053-z
East Asians tend towards holistic styles of thinking whereas Westerners generally think more analytically. Recent work has shown that Western participants perceive emotional expressions in a somewhat holistic manner, however. Specifically, Westerners interpret emotional facial expressions differently when presented with a body displaying a congruent versus incongruent emotional expression. Here, we examined how processing these face-body combinations varies according to cultural differences in thinking style. Consistent with their proclivity towards contextual focus, Japanese perceivers focused more on the body when judging the emotions of face-body composites. Moreover, in line with their greater tendency towards holistic perceptual processing, we found that pairing facial expressions of emotion with emotionally congruent bodies facilitated Japanese participants’ recognition of faces’ emotions to a greater degree than it did for Canadians. Similarly, incongruent face-body combinations impaired facial emotion recognition more for Japanese than Canadian participants. These findings extend work on cultural differences in emotion recognition from interpersonal to intrapersonal contexts with implications for intercultural understanding.
Anderson, C. A., Suzuki, K.(鈴木佳苗), Swing, E. L., Groves, C. L., Gentile, D. A., Prot, S., Lam, C. P., Sakamoto, A.(坂元 章), Horiuchi, Y.(堀内由樹子), Krahé, B., Jelic, M., Liuqing, W., Toma, R., Warburton, W. A., Zhang, X., Tajima, S.(田島 祥), Qing, F., & Petrescu, P. (2017). Media violence and other aggression risk factors in seven nations. 7か国におけるメディア暴力と他の攻撃リスク要因 Personality and Social Psychology Bulletin, 43(7), 986-998. doi:10.1177/0146167217703064
Cultural generality versus specificity of media violence effects on aggression was examined in seven countries (Australia, China, Croatia, Germany, Japan, Romania, the United States). Participants reported aggressive behaviors, media use habits, and several other known risk and protective factors for aggression. Across nations, exposure to violent screen media was positively associated with aggression. This effect was partially mediated by aggressive cognitions and empathy. The media violence effect on aggression remained significant even after statistically controlling a number of relevant risk and protective factors (e.g., abusive parenting, peer delinquency), and was similar in magnitude to effects of other risk factors. In support of the cumulative risk model, joint effects of different risk factors on aggressive behavior in each culture were larger than effects of any individual risk factor.
Komoto, Y., Shoun, A.(祥雲暁代), Akiyama, K., Sakamoto, A.(坂元章) et al. (2017). Development and validation of the Pachinko/Pachi-Slot Playing Ambivalence Scale. パチンコ・パチスロ遊技両価性尺度の開発と妥当化 Asian Journal of Gambling Issues and Public Health, 7(3) . DOI: 10.1186/s40405-017-0023-6
A scale aimed at measuring ambivalence among people with pachinko/pachi-slot playing disorder, the Pachinko/Pachi-Slot Playing Ambivalence Scale (PPAS), was developed and its reliability and validity ascertained.
A total of 522 participants (average year: 48.0) who were residing in Tokyo Metropolitan Area, and had played pachinko within the previous year completed questions relating to demographics, four gambling-related scales (including South Oaks Gambling Screen) and two general ambivalence scales (including Ambivalence over Emotional Expressiveness Questionnaire).
Internal consistency (α = 0.87) and test–retest reliability (r = 0.66) were confirmed. The PPAS’s score was associated with each related scale’s score (r = 0.37–0.62).
The PPAS was shown to be consistent with previous scales and useful in clinical settings
Kawamura, Y. (河村悠太), & Kusumi, T. (楠見孝) (2018). Relationships between two types of reputational concern and altruistic behavior in daily life. 2種類の評判への関心と日常の利他行動の関連. Personality and Individual Differences, 121, 19-24. doi: 10.1016/j.paid.2017.09.003
Although many studies have shown that reputational cues promote altruism, few studies have focused on individual differences. The present study provides novel evidence indicating that the relationship between reputational concern and altruistic behavior differs according to the type of reputational concern involved and the recipients of altruism. Specifically, the relationships between individual differences of two reputational concerns (i.e., praise seeking and rejection avoidance) and the frequency with which participants exhibited altruistic behavior toward various individuals (i.e., family members, friends/acquaintances, and strangers) were examined. As predicted, neither type of reputational concern was significantly associated with altruistic behavior toward family members. This is understandable, as altruistic behavior toward familiar people is unlikely to lead to a good reputation. Conversely, praise seeking predicted altruistic behavior toward friends/acquaintances and strangers, whereas rejection avoidance did not. These findings are consistent with recent literature suggesting the effectiveness of positive reputation systems to promote generosity, relative to negative reputation systems. Furthermore, rejection avoidance was negatively associated with altruistic behavior toward strangers; we discussed the possibility that this was because such behavior was not very normative. Our findings provide useful insight for future studies examining the relationship between reputation and altruistic behavior.
Kawamura, Y. (河村悠太), & Kusumi, T. (楠見孝) (2017). The norm-dependent effect of watching eyes on donation. "見つめる目"の規範依存的効果の検討. Evolution and Human Behavior, 38(5), 659-666. doi: 10.1016/j.evolhumbehav.2017.05.003
Although many previous studies have shown that eye-like images promote generosity, the mechanism of this “watching eyes effect” remains unclear. One possible cause is the concern for a good reputation as a generous person, while the other is the concerns for a bad reputation as a norm violator. To elucidate which of these two concerns is the main influencer, the present study conducted a laboratory experiment that investigated whether the watching eyes effect changed depending on social norms. If the concern for a good reputation leads to the effect, prosocial behavior would be more likely in the presence of watching eyes, regardless of the social norms involved. However, if the concern for avoiding a bad reputation as a norm violator leads to the effect, watching eyes promote prosocial behavior only in the existence of prosocial norms. In the original study, participants were asked to make a charitable donation under conditions in which eye-like images either were or were not present. In addition to the eye-like images, we manipulated prosocial norms by informing each participant of either high or low mean donation amounts given by previous participants. We found that watching eyes promoted donations only when a prosocial norm existed. This supports the idea that the watching eyes effect is caused by a concern for avoiding a bad reputation from violating norms. However, in a replication study, we were unable to replicate the original results; watching eyes did not promote generosity regardless of the norm. Taken together, we discussed the moderation effect of norms and the possibility of other moderators.
Kawamoto, T. (川本大史) & Furutani, K. (古谷嘉一郎) (2018). The mediating role of intolerance of uncertainty on the relationships between perfectionism dimensions and psychological adjustment/maladjustment among mothers 母親の完全主義次元と心理適応・不適応との関連に対する不確実さ不耐性の媒介効果 Personality and Individual Differences, 122, 62-67. doi: 10.1016/j.paid.2017.10.008
The present study investigated a possible mediating effect of intolerance of uncertainty (IU) on the relationship between perfectionism and psychological adjustment/maladjustment as well as the unique and common effects of perfectionism dimensions—personal standards (PS) and concern over mistakes (CM)—on these constructs. Five hundred mothers participated an online survey, completing measures of perfectionism (PS and CM), IU, and psychological adjustment/maladjustment (life satisfaction, depression, and rearing stress). We found that both PS and CM were positively correlated with IU. Mediation analyses indicated that IU mediated the relationship between CM and psychological adjustment/maladjustment regardless of whether PS were partialled out. In contrast, IU had a suppression effect on the relationship between PS and psychological adjustment/maladjustment, but only when CM was not partialled out. Commonality regression analysis revealed that the unique effect of PS on IU (< 0.1%) was much smaller than the common effects of PS and CM on IU (12.3%). In addition, CM had stronger unique effects on all variables than did PS. These findings highlight the importance of investigating both the unique and common effects of perfectionism dimensions on outcome variables. Our findings further our understanding of the mechanisms underlying the relationships between perfectionism dimensions and psycho- logical adjustment/maladjustment.
Ishii, K. (石井敬子), Mojaverian, T., Masuno, K., & Kim, H. S. (2017). Cultural Differences in Motivation for Seeking Social Support and the Emotional Consequences of Receiving Support: The Role of Influence and Adjustment Goals. ソーシャルサポートを求める際の動機づけとそれを受け取ることの感情的な帰結における文化差：影響と調整志向の役割 Journal of Cross-Cultural Psychology, 48(9), 1442-1456. doi: 10.1177/0022022117731091
Previous research suggests that the benefits of different types of social support depend on cultural background. However, cultural variations in the underlying motivations for seeking social support and the emotional implications of receiving support have not yet been clearly explored. We hypothesized and found that European Americans emphasized the motivation for self-esteem as a factor in deciding to seek explicit social support (e.g., advice, emotional comfort), whereas Japanese emphasized relational concerns as a factor in deciding to seek implicit social support (e.g., the emotional comfort experienced without disclosing one’s problems). Furthermore, European Americans anticipated experiencing strong feelings of self-esteem and pride regarding receiving support, whereas Japanese anticipated experiencing strong feelings of shame and guilt. Additionally, influence goals mediated cultural differences in the motivation for self-esteem and the experience of self-esteem and pride, whereas adjustment goals mediated cultural differences in relational concerns and the experience of shame and guilt.
Masuda, T. (増田貴彦), Ishii, K. (石井敬子), Miwa, K., Rashid, M., Lee, H., & Mehdi, R. (2017). One label or Two? Linguistic Influences on the Similarity Judgment of Objects Between English and Japanese Speakers. 1つのラベルか、それとも2つのラベルか? 英語と日本語話者間での物の類似性判断における言語の影響 Frontiers in Psychology, 8, 1637 doi: 10.3389/fpsyg.2017.01637
Recent findings have re-examined the linguistic influence on cognition and perception, while identifying evidence that supports the Whorfian hypothesis. We examine how English and Japanese speakers perceive similarity of pairs of objects, by using two sets of stimuli: one in which two distinct linguistic categories apply to respective object images in English, but only one linguistic category applies in Japanese; and another in which two distinct linguistic categories apply to respective object images in Japanese, but only one applies in English. We conducted four studies and tested different groups of participants in each of them. In Study 1, we asked participants to name the two objects before engaging in the similarity judgment task. Here, we expected a strong linguistic effect. In Study 2, we asked participants to engage in the same task without naming, where we assumed that the condition is close enough to our daily visual information processing where language is not necessarily prompted. We further explored whether the language still influences the similarity perception by asking participants to engage in the same task basing on the visual similarity (Study 3) and the functional similarity (Study 4). The results overall indicated that English and Japanese speakers perceived the two objects to be more similar when they were in the same linguistic categories than when they were in different linguistic categories in their respective languages. Implications for research testing the Whorfian hypothesis and the requirement for methodological development beyond behavioral measures are discussed.
Takano, Y., Ukezono, M., Nakashima, S. F. (中嶋智史), Takahashi, N., & Hironaka, N. (2017). Learning of efficient behaviour in spatial exploration through observation of behaviour of conspecific in laboratory rats. 実験室ラットの空間探索における他個体の行動の観察を通じた効率的行動の学習 Royal Society Open Science, 4, 170121 doi: 10.1098/rsos.170121
Recent studies have suggested that rodent behaviour is influenced by the behaviour of surrounding conspecifics (e.g. emotional contagion and prosocial behaviour). However, little is known about deferred imitation and complex observational learning in rats. The purpose of this study was to reveal whether rats can learn from another rat’s experiences. In a maze, observer rats watched the foraging behaviour of other rats (demonstrators) and then foraged in turn. The results showed that demonstrators explored inefficiently, but observers explored more efficiently after observing inefficient exploration by the demonstrators. This observational learning probably involved the acquisition of an efficient strategy through spatial exploration.
Miyajima, T. (宮島健), & Yamaguchi, H. (山口裕幸) (2017). I Want to but I Won't: Pluralistic Ignorance Inhibits Intentions to Take Paternity Leave in Japan. 取りたいけど取らない: 多元的無知が日本における男性の育児休業の取得意図を抑制する Frontiers in Psychology, 8, 1508. doi: 10.3389/fpsyg.2017.01508
The number of male employees who take paternity leave in Japan has been low in past decades. However, the majority of male employees actually wish to take paternity leave if they were to have a child. Previous studies have demonstrated that the organizational climate in workplaces is the major determinant of male employees’ use of family-friendly policies, because males are often stigmatized and fear receiving negative evaluation from others. While such normative pressure might be derived from prevailing social practices relevant to people’s expectation of social roles (e.g., “Men make houses, women make homes”), these social practices are often perpetuated even after the majority of group members have ceased to support them. The perpetuation of this unpopular norm could be caused by the social psychological phenomenon of pluralistic ignorance. While researches have explored people’s beliefs about gender roles from various perspectives, profound understanding of these beliefs regarding gender role norms, and the accuracy of others’ beliefs remains to be attained. The current research examined the association between pluralistic ignorance and the perpetually low rates of taking paternity leave in Japan. Specifically, Study 1 (n = 299) examined Japanese male employees’ (ages ranging from the 20 s to the 40 s) attitudes toward paternity leave and to estimate attitudes of other men of the same age, as well as behavioral intentions (i.e., desire and willingness) to take paternity leave if they had a child in the future. The results demonstrated that male employees overestimated other men’s negative attitudes toward paternity leave. Moreover, those who had positive attitudes toward taking leave and attributed negative attitudes to others were less willing to take paternity leave than were those who had positive attitudes and believed others shared those attitudes, although there was no significant difference between their desires to take paternity leave. Study 2 (n = 425) replicated these results and further indicated that they could not be explained by the participants’ needs to be socially desirable. Together, our findings suggest that pluralistic ignorance occurs in the context of taking paternity leave in Japanese men, and this leads to the low use of available paternity leave.
Kosugi,K.E.（小杉考司）(2017). Asymmetrical triadic relationship based on the structural difficulty. 構造的困難度に基づく非対称な三者関係の分析 Behaviormetrika,44(2),1--17. doi: 10.1007/s41237-017-0033-9
Using Bayesian inference, this study aims to estimate the magnitude of the cognitive load when a person perceives asymmetric social relations. Some empirical evidence relating to balance theory has shown that a balanced state is comparatively easier to memorize than an unbalanced one. In this study, since a balanced state is defined by structural complexity, an experimental hypothesis was set whereby asymmetric social relationships have different difficulty levels depending on structural complexity. The balanced state of an asymmetric relation as structural difficulty is formally derived from the eigenvalue structure of a Hermitian matrix. Asymmetric triadic relations are modeled as featuring three kinds of structural difficulties according to the eigenvalue decomposition of the Hermitian matrix and pattern-specific difficulties. The differences among the structural difficulties were not sufficiently significant to exceed pattern-specific difficulties, but the Bayes factor of the informational hypothesis of this research yielded positive effects.
Kawamoto, T. (川本大史) (2017). What happens in your mind and brain when you are excluded from a social activity? 社会的に排斥されるとあなたのこころと脳で何が起こるのだろうか？ Frontiers for Young Minds, 5:46. doi: 10.3389/frym.2017.00046
In school and in everyday life, we sometimes experience rejection by classmates, or we might see someone being excluded from an activity. What do excluded individuals feel? How does the brain process information about being socially excluded? In the past few decades, psychologists and social neuroscientists have investigated the influence of social exclusion on our mind, brain, and behavior. Social exclusion is a complex and ambiguous phenomenon, and therefore, we process information about it dynamically and often cope with it flexibly. In this article, I have described the dynamic effects of social exclusion on our mind, brain, and behavior by developing a model of what happens in the brain and the actions people take upon experiencing social exclusion.
Tanibe, T. (谷辺哲史), Hashimoto, T. (橋本剛明), & Karasawa, K. (唐沢かおり) (2017). We perceive a mind in a robot when we help it. ロボットを助けるとロボットに心を感じる PLoS ONE, 12(7): e0180952.
People sometimes perceive a mind in inorganic entities like robots. Psychological research has shown that mind perception correlates with moral judgments and that immoral behaviors (i.e., intentional harm) facilitate mind perception toward otherwise mindless victims. We conducted a vignette experiment (N = 129; Mage = 21.8 ± 6.0 years) concerning human-robot interactions and extended previous research’s results in two ways. First, mind perception toward the robot was facilitated when it received a benevolent behavior, although only when participants took the perspective of an actor. Second, imagining a benevolent interaction led to more positive attitudes toward the robot, and this effect was mediated by mind perception. These results help predict what people’s reactions in future human-robot interactions would be like, and have implications for how to design future social rules about the treatment of robots.
Matsunaga, M., Ishii, K. (石井敬子), Ohtsubo, Y. (大坪庸介), Noguchi, Y., Ochi, M. (越智美早), & Yamasue, H. (2017). Association between salivary serotonin and the social sharing of happiness. 唾液セロトニンと幸せの社会的共有との関連 PloS ONE, 12(7), e0180391. doi: 10.1371/journal.pone.0180391
Although human saliva contains the monoamine serotonin, which plays a key role in the modulation of emotional states, the association between salivary serotonin and empathic ability remains unclear. In order to elucidate the associations between salivary serotonin levels, trait empathy, and the sharing effect of emotions (i.e., sharing emotional experiences with others), we performed a vignette-based study. Participants were asked to evaluate their happiness when they experience several hypothetical life events, whereby we manipulated the valence of the imagined event (positive, neutral, or negative), as well as the presence of a friend (absent, positive, or negative). Results indicated that the presence of a happy friend significantly enhanced participants’ happiness. Correlation analysis demonstrated that salivary serotonin levels were negatively correlated with happiness when both the self and friend conditions were positive. Correlation analysis also indicated a negative relationship between salivary serotonin levels and trait empathy (particularly in perspective taking), which was measured by the Interpersonal Reactivity Index. Furthermore, an exploratory multiple regression analysis suggested that mothers’ attention during childhood predicted salivary serotonin levels. Our findings indicate that empathic abilities and the social sharing of happiness decreases as a function of salivary serotonin levels.
Oishi, S., Yagi, A. (八木彩乃), Komiya, A. (小宮あすか), Kohlbacher, F., Kusumi, T. (楠見孝), & Ishii, K (石井敬子). (2017). Does a major earthquake change job preferences and human values? 大地震は職業の好みや人間の価値観を変えるのか？ European Journal of Personality, 31, 258-265. doi: 10.1002/per.2102
Does a major natural disaster change human values and job preferences? The present studies examined whether the experience of a natural disaster experience shifts people’s values and job preferences toward pro-social directions. In Study 1 (cross-temporal analysis), we analysed job application data in nine cities in Japan over 12 years and found that the popularity of pro-social occupations (e.g. firefighter) increased after the Great Hanshin–Awaji Earthquake in 1995, in particular the area hit hardest by the quake. In Study 2 (a large national survey), we found that Japanese respondents who had experienced a major earthquake are more likely to hold a pro-social job than those who never experienced a major earthquake. Together, the current findings suggest that the experience of a major natural disaster shifts human values from the egocentric to the allocentric direction, which in turn could result in a social structure that values pro-social occupations.
Ohtsubo, Y.（大坪庸介）, & Yamaguchi, C.（山口千晶） (2017). People are more generous to a partner who pays attention to them. Evolutionary Psychology, 15 (1). doi: 10.1177/1474704916687310
People use relatively low-cost signals to maintain close relationships, in which they engage in costlier exchanges of tangible support. Paying attention to a partner allows an individual to communicate his or her interest in the relationship with the partner. Previous studies have revealed that when Person A pays attention to Person B, B’s feeling of intimacy toward A increases. If social attention strengthens the bond between A and B, it is predicted that A’s attention will also increase B’s generous behavior toward A. This study tested this prediction. Participants first engaged in a collaborative task using computers. In the task, the putative partner (a computer program) either paid or did not pay attention to participants (high attention condition vs. low attention condition). In the control condition, the partner could not choose when to pay attention to participants. They then played three rounds of the dictator game with the partner. Confirming the previous finding, perceived intimacy was highest in the high attention condition, in the middle in the control condition, and lowest in the low attention condition. More importantly, participants in the high attention condition decided to give more resources to their partner than those in the low attention condition (but the difference between the high attention condition and the control condition was not significant). In addition, self-reported intimacy was positively correlated with the resource allocated to the partner. The results of this study demonstrated that social attention fosters a partner’s generosity.
Yamaguchi, M.（山口真奈）, Smith, A.（スミス，アダム）, & Ohtsubo, Y.（大坪庸介） (2017). Loneliness predicts insensitivity to partner commitment. Personality and Individual Differences, 105, 200-207. doi: 10.1016/j.paid.2016.09.047
People attend to their partners’ pro-relationship behaviors (or commitment signals) which in turn leads to a positive adjustment in perceived strength of interpersonal bonds. This bond-confirming effect is stronger when the commitment signal entails some high cost (e.g., receiving an expensive birthday present), and by contrast, it is weaker when the commitment signal entails a low cost (e.g., receiving a wish of “Happy Birthday”). The present study explored how loneliness moderates sensitivity to commitment signals as well as their absence (i.e., situations where partners fail to signal commitment despite the demands of the situation). Studies with a Japanese student sample (Study 1), a Japanese community sample (Study 2), and an American sample drawn from users of Amazon Mechanical Turk (Study 3) found that loneliness is associated with an insensitivity to commitment signals: The lonelier the participant, the less likely he or she was to positively adjust perceived bond strength in response to a commitment signal. This relative insensitivity was observed irrespective of the costliness of the signal. On the other hand, loneliness did not predict differences in sensitivity to the absence of commitment signals. Implications of these results for the loneliness literature are discussed.
Kusumi, T.（楠見 孝）, Hirayama, R., & Kashima, Y.(2017). Risk Perception and Risk Talk: The Case of the Fukushima Daiichi Nuclear Radiation Risk. リスクの認知と会話：福島原発事故による放射線リスク Risk Analysis: An International Journal. (電子版) doi:10.1111/risa.12784
Individuals’ perceptions and their interpersonal communication about a risk event, or risk talk, can play a significant role in the formation of societal responses to the risk event. As they formulate their risk opinions and speak to others, risk information can circulate through their social networks and contribute to the construction of their risk information environment. In the present study, Japanese citizens’ risk perception and risk talk were examined in the context of the Fukushima Daiichi nuclear radiation risk. We hypothesized and found that the risk information environment and risk literacy (i.e., competencies to understand and use risk information) interact to influence their risk perception and risk talk. In particular, risk literacy tends to stabilize people’s risk perceptions and their risk communications. Nevertheless, there were some subtle differences between risk perception and communication, suggesting the importance of further examination of interpersonal risk communication and its role in the societal responses to risk events.
Shiraki, Y.（白木優馬）& Igarashi, T.（五十嵐祐） (2017). We Can’t Return Evil for Good: The Comparison between Direct and Indirect Reciprocity. 恩を仇で返せない：直接互恵性と間接互恵性の比較 Letters on Evolutionary Behavioral Science, 8(1), 4-7.
There are two distinct evolutionary mechanisms of altruistic behavior: direct and indirect reciprocity. Humans are motivated not only to reciprocate benefits to benefactors but also to behave altruistically for the maintenance or improvement of their reputation. This study compared the two evolutionary mechanisms of altruistic behavior. Three scenario-based experiments on diverse samples (Japanese undergraduates in Experiment 1, Japanese crowdsourcing workers in Experiment 2, and crowdsourcing workers worldwide in Experiment 3) were conducted by manipulating (1) reciprocity between participants and a colleague (reciprocal or non-reciprocal) and (2) the colleague’s reputation in the workplace (good or bad). When participants received a reciprocal request from their colleague to help, they tended to accept it, even if the colleague had a bad reputation among others. On the other hand, participants were less accepting of a non-reciprocal request from a colleague with a bad reputation than a colleague with a good reputation. These results clearly indicate that humans prioritize the maintenance of direct reciprocal relationships over group-based reputations.
Fugate, J. M. B., Gendron, M., Nakashima, S. F. (中嶋智史), & Barrett, L. F. (2017). Emotion Words: Adding Face Value. 感情語：顔の意味を付加する Emotion.
Despite a growing number of studies suggesting that emotion words affect perceptual judgments of emotional stimuli, little is known about how emotion words affect perceptual memory for emotional faces. In Experiments 1 and 2 we tested how emotion words (compared with control words) affected participants’ abilities to select a target emotional face from among distractor faces. Participants were generally more likely to false alarm to distractor emotional faces when primed with an emotion word congruent with the face (compared with a control word). Moreover, participants showed both decreased sensitivity (d′) to discriminate between target and distractor faces, as well as altered response biases (c; more likely to answer “yes”) when primed with an emotion word (compared with a control word). In Experiment 3 we showed that emotion words had more of an effect on perceptual memory judgments when the structural information in the target face was limited, as well as when participants were only able to categorize the face with a partially congruent emotion word. The overall results are consistent with the idea that emotion words affect the encoding of emotional faces in perceptual memory.
Ozono, H.（大薗博記）, Kamijo, Y., & Shimizu, K. (2016). Institutionalize reciprocity to overcome the public goods provision problem 互恵性の制度化による公共財供給問題の解決 PLoS ONE, 11(6), e0154321. doi: 10.1371/journal.pone.0154321
Cooperation is fundamental to human societies, and one of the important paths for its emergence and maintenance is reciprocity. In prisoner’s dilemma (PD) experiments, reciprocal strategies are often effective at attaining and maintaining high cooperation. In many public goods (PG) games or n-person PD experiments, however, reciprocal strategies are not successful at engendering cooperation. In the present paper, we attribute this difficulty to a coordination problem against free riding among reciprocators: Because it is difficult for the reciprocators to coordinate their behaviors against free riders, this may lead to inequality among players, which will demotivate them from cooperating in future rounds. We propose a new mechanism, institutionalized reciprocity (IR), which refers to embedding the reciprocal strategy as an institution (i.e., institutionalizing the reciprocal strategy). We experimentally demonstrate that IR can prevent groups of reciprocators from falling into coordination failure and achieve high cooperation in PG games. In conclusion, we argue that a natural extension of the present study will be to investigate the possibility of IR to serve as a collective punishment system.
Ozono, H.（大薗博記）, Jin, N.（神信人）, Watabe, M.（渡部幹）, & Shimizu, K. (2016). Solving the second-order free rider problem in a public goods game: An experiment using a leader support system 公共財ゲームにおける2次的フリーライダー問題の解決：リーダーサポートシステムによる実験 Scientific Reports, 6, 38349. doi: 10.1038/srep38349
Punishment of non-cooperators—free riders—can lead to high cooperation in public goods games (PGG). However, second-order free riders, who do not pay punishment costs, reduce the effectiveness of punishment. Here we introduce a “leader support system,” in which one group leader can freely punish group followers using capital pooled through the support of group followers. In our experiment, participants engage in three stages repeatedly: a PGG stage in which followers decide to cooperate for their group; a support stage in which followers decide whether to support the leader; and a punishment stage in which the leader can punish any follower. We compare a support-present condition with a no-support condition, in which there is an external source for the leader’s punishment. The results show that punishment occurs more frequently in the support-present condition than the no-support condition. Within the former, both higher cooperation and higher support for a leader are achieved under linkage-type leaders—who punish both non-cooperators and non-supporters. In addition, linkage-type leaders themselves earn higher profits than other leader types because they withdraw more support. This means that leaders who effectively punish followers could increase their own benefits and the second-order free rider problem would be solved.
Yamagishi, T. (山岸俊男), Matsumoto, Y.(松本良恵), Kiyonari, T.(清成透子), Takagishi, H.(高岸治人), Li, Y.(李楊), Kanai, R., & Sakagami, M. (2017). Response time in economic games reflects different types of decision conflict for prosocial and proself individuals 経済ゲームにおける反応時間は向社会的と向自己的個体の決定コンフリクトの違いを反映する Proceedings of the National Academy of Science of the United States of America (Published online before print May 30, 2017) doi: 10.1073/pnas.1608877114
Behavioral and neuroscientific studies explore two pathways through which internalized social norms promote prosocial behavior. One pathway involves internal control of impulsive selfishness, and the other involves emotion-based prosocial preferences that are translated into behavior when they evade cognitive control for pursuing self-interest. We measured 443 participants’ overall prosocial behavior in four economic games. Participants’ predispositions [social value orientation (SVO)] were more strongly reflected in their overall game behavior when they made decisions quickly than when they spent a longer time. Prosocially (or selfishly) predisposed participants behaved less prosocially (or less selfishly) when they spent more time in decision making, such that their SVO prosociality yielded limited effects in actual behavior in their slow decisions. The increase (or decrease) in slower decision makers was prominent among consistent prosocials (or proselfs) whose strong preference for prosocial (or proself) goals would make it less likely to experience conflict between prosocial and proself goals. The strong effect of RT on behavior in consistent prosocials (or proselfs) suggests that conflict between prosocial and selfish goals alone is not responsible for slow decisions. Specifically, we found that contemplation of the risk of being exploited by others (social risk aversion) was partly responsible for making consistent prosocials (but not consistent proselfs) spend longer time in decision making and behave less prosocially. Conflict between means rather than between goals (immediate versus strategic pursuit of self-interest) was suggested to be responsible for the time-related increase in consistent proselfs’ prosocial behavior. The findings of this study are generally in favor of the intuitive cooperation model of prosocial behavior.
Ogihara, Y. (荻原祐二). (2017). Temporal changes in individualism and their ramification in Japan: Rising individualism and conflicts with persisting collectivism. 日本における個人主義傾向の経時的変化とその心理的帰結：増加する個人主義と維持された集団主義との葛藤 Frontiers in Psychology, 8, 695.
Many studies have shown that American culture has become more individualistic over time. However, it was unclear whether other cultures, especially East Asian cultures, have also shifted toward greater individualism. Therefore, this article reviewed studies investigating temporal changes in individualism in Japan and their ramifications on psychology and behavior. Japan has experienced rapid and dramatic economic growth and urbanization and has adopted more social systems based on individualistic concepts in various contexts (e.g., workplace, school). Recent studies have suggested that, along with these socioeconomic changes, Japanese culture has become more individualistic over time. Specifically, the divorce rate increased and household size decreased. Moreover, people give more unique names to their children and dogs, and individualistic words such as “individual” and “uniqueness” appear more frequently in newspapers. Furthermore, social values became more individualistic. Yet, it has also been shown that some collectivistic values still remain. As a result, people have difficulty in adapting to this coexistence, which injures interpersonal relationships and well-being. This paper discussed how Japanese culture changed over time and how such changes affected Japanese psychology and behavior.
Ishii, K. (石井健一) (2017). A Comparative Study between Japanese, US, Taiwanese, and Chinese Social Networking Site Users: Self-Disclosure and Network Homogeneity. (日本、米国、台湾、中国のSNS利用者の比較―自己開示とネットワークの同質性) In Ana Serrano Telleria (ed), Between the Public and Private in Mobile Communication, New York: Routledge, pp.155-174. ISBN-13: 978-1138225558
This study compares Facebook users in Japan, the US, and Taiwan, and users of similar SNSs in China, focusing on their self-disclosure and network characteristics. An online questionnaire survey was conducted in these four countries in 2012/2013. Results indicate that mobile device users use SNS more frequently than desktop/laptop PC users. Results also indicate that cultural differences in SNS use were observed. Across these four countries, the Japanese have the smallest number of Facebook friends; the highest level of homogeneity in their friendship network; the highest proportion of offline friends; are least likely to disclose personally identifiable information; and most frequently read and post messages on Facebook. In contrast, the Chinese are most likely to disclose personal attribute information and Taiwanese are most likely to disclose personal information on SNS. The Japanese also show a positive and significant correlation between network homogeneity, number of Facebook friends, and disclosure of personal information, which suggests that they depend on offline homogeneous relationships more than SNS users in other countries for their Facebook friending process. Structural equation model results indicate that cultural differences in self-disclosure on SNS between Japanese, Taiwanese, and Chinese users are partially explained by relational mobility.
Aiba, M. (相羽美幸), Tachikawa, H., Fukuoka,Y. (福岡欣治), Lebowitz, A., Shiratori, Y., Doi, N., & Matsui, Y. (松井豊) (2017). Standardization of Brief Inventory of Social Support Exchange Network (BISSEN) in Japan. 日本における簡易ソーシャル・サポート・ネットワーク尺度 (BISSEN) の標準化 Psychiatry Research, 253, 364-372. doi: 10.1016/j.psychres.2017.03.056
This study describes the Brief Inventory of Social Support Exchange Network (BISSEN) as a standardized brief inventory measuring various aspects of social support. We confirmed the reliability and validity for function and direction of support and standardized the BISSEN. For Sample 1, a stratified random sampling method was used to select 5200 residents in Japan. We conducted mail surveys and responses were retrieved from 2274 participants (collection rate 43.7%). Participants completed a questionnaire packet that included BISSEN, suicidal ideation, depression, support seeking, and Multidimensional Scale of Perceived Social Support (MSPSS). Sample 2 surveys for test-retest reliability were conducted on 23 residents at approximately two-week intervals. Participants were asked about gender, age, and BISSEN. First, we assessed the internal consistency, test-retest reliability, construct, convergent, and concurrent validity. McDonald’s omega (.73–.92) and test-retest correlations (.78–.85) demonstrated adequate internal consistency and test-retest reliability. Depression, support seeking, and MSPSS were significantly correlated with all scores of BISSEN. The non-suicidal ideation group had significantly more support compared to the suicidal ideation group. Therefore, function and direction of support in BISSEN had sufficient reliability and validity. Next, we standardized BISSEN using Z-scores and percentile rank with respect to each 12 norm groups by age and gender.
8項目で受領サポートと提供サポートをどちらも測定できるソーシャル・サポート・ネットワーク尺度を作成し、性年代別に標準化しました。標準化の換算表はSupplemental Materialsに入っています。日本語の項目は、精神医学55巻9号pp.863-873「簡易ソーシャル・サポート・ネットワーク尺度 (BISSEN) の開発」をご覧ください。
Kohama, S., Inamasu, K.（稲増一憲）, & Tago, A. (2017). To denounce, or not to denounce: Survey experiments on diplomatic quarrels. 糾弾すべきか，せざるべきか：パブリック・ディプロマシーについてのサーベイ実験 Political Communication, 34(2), 243-260 doi: 10.1080/10584609.2016.1200700
Despite widespread concern over heated diplomatic debates and growing interest in public diplomacy, it is still incompletely understood what type of message is more effective for gaining support from foreign public, or the international society, in situations where disputing countries compete in diplomatic campaigns. This study, through multiple survey experiments, uncovers the effect of being silent, issuing positive justification, and negative accusation, in interaction with the opponent’s strategy. We demonstrate that negative verbal attacks “work” and undermine the target’s popularity as they do in electoral campaigns. Unlike domestic electoral campaigns, however, negative diplomacy has little “backlash” and persuades people to support the attacker. Consequently, mutual verbal fights make neither party more popular than the other. Nevertheless, this does not discourage disputants from waging verbal fights due to the structure similar to the one-shot prisoner’s dilemma. We also find that positive messages are highly context-dependent—that is, their effects greatly depend on the opponent’s strategy and value proximity between the messenger and the receiver.
Lee, Jinah(李 津娥)(2017). Japanese Political Advertising in a Changing Media and Electoral Environment. 変化するメディアと選挙環境における日本の政治広告 In Holtz-Bacha, Christina & Just, Marion R.(eds). Routledge Handbook of Political Advertising. New York: Routledge, pp.353-365. ISBN-13: 978-1138908307
This Handbook provides the most comprehensive overview of the role of electoral advertising on television and new forms of advertising in countries from all parts of the world currently available. Thematic chapters address advertising effects, negative ads, the perspective of practitioners and gender role. Country chapters summarize research on issues including political and electoral systems; history of ads; the content of ads; reception and effects of ads; regulation of political advertising on television and the Internet; financing political advertising; and prospects for the future. The Handbook confirms that candidates spend the major part of their campaign budget on television advertising. The US enjoys a special situation with almost no restrictions on electoral advertising whereas other countries have regulation for the time, amount and sometimes even the content of electoral advertising or they do not allow television advertising at all. The role that television advertising plays in elections is dependent on the political, the electoral and the media context and can generally be regarded as a reflection of the political culture of a country. The Internet is relatively unregulated and is the channel of the future for political advertising in many countries.
Seo, K., Motoyoshi, T.(元吉忠寛), & Maeda, Y. (2016). Risk Perceptions of Resuming Nuclear Power Plant Operations After Fukushima: A Student Survey. 福島第一原子力発電所事故後の原子力発電所再稼働に関するリスク認知:学生を対象とした調査 Journal of Disaster Research, 11, 789-797. doi: 10.20965/jdr.2016.p0789
Quake-induced accident of Fukushima nuclear power plant in 2011 triggered heated argument about the country’s energy policy in Japan. Although many people recognized the risk of nuclear energy use, they did not necessarily support the option of abandoning the technology for the near future. This paper focuses on how people perceive risks associated with and without nuclear power generation and how perceived risks affect their opinion. We conducted questionnaire survey targeting 18–20 year old university students, the stakeholders in the future. The survey was implemented in 2013–2014 when none of Japan’s nuclear power plants was in active use. Three quarters of the respondents answered that a future with nuclear power generation was more realistic than without it. The aspects dividing the two groups, i.e., respondents who expect a future with or without nuclear energy use were their evaluations of three themes: (1) the feasibility of renewable energy sources, (2) the impacts in the safety of developing nations’ nuclear power generation, and (3) the difficulty in gaining the acceptance of residents near the power plants. Meanwhile, both groups above were similarly positive about technological innovation, and were similarly and strongly negative about developing safety management.
Majima, Y. (眞嶋良全), Nishiyama K., Nishihara A., Hata, R. (2017). Conducting Online Behavioral Research Using Crowdsourcing Services in Japan. 国内クラウドソーシングサービスを用いたオンライン行動研究 Frontiers in Psychology, 8:378. doi: 10.3389/fpsyg.2017.00378
Recent research on human behavior has often collected empirical data from the online labor market, through a process known as crowdsourcing. As well as the United States and the major European countries, there are several crowdsourcing services in Japan. For research purpose, Amazon’s Mechanical Turk (MTurk) is the widely used platform among those services. Previous validation studies have shown many commonalities between MTurk workers and participants from traditional samples based on not only personality but also performance on reasoning tasks. The present study aims to extend these findings to non-MTurk (i.e., Japanese) crowdsourcing samples in which workers have different ethnic backgrounds from those of MTurk. We conducted three surveys (N = 426, 453, 167, respectively) designed to compare Japanese crowdsourcing workers and university students in terms of their demographics, personality traits, reasoning skills, and attention to instructions. The results generally align with previous studies and suggest that non-MTurk participants are also eligible for behavioral research. Furthermore, small screen devices are found to impair participants’ attention to instructions. Several recommendations concerning this sample are presented.
Majima, Y. (眞嶋良全) (2017). The Feasibility of a Japanese Crowdsourcing Service for Experimental Research in Psychology. 心理学の実験研究における国内クラウドソーシングサンプルの可能性 SAGE Open, 7(1). doi: 10.1177/2158244017698731
Recent studies have empirically validated the data obtained from Amazon’s Mechanical Turk. Amazon’s Mechanical Turk workers behaved similarly not only in simple surveys but also in tasks used in cognitive behavioral experiments that employ multiple trials and require continuous attention to the task. The present study aimed to extend these findings to data from Japanese crowdsourcing pool in which participants have different ethnic backgrounds from Amazon’s Mechanical Turk workers. In five cognitive experiments, such as the Stroop and Flanker experiments, the reaction times and error rates of Japanese crowdsourcing workers and those of university students were compared and contrasted. The results were consistent with those of previous studies, although the students responded more quickly and poorly than the workers. These findings suggested that the Japanese crowdsourcing sample is another eligible participant pool in behavioral research; however, further investigations are needed to address issues of qualitative differences between student and worker samples.
Inaba, M. (稲葉美里), Takahashi, N. (高橋伸幸), Ohtsuki, H. (2016). Robustness of linkage strategy that leads to large-scale cooperation. 大規模協力の達成を可能にする連結戦略の頑健性 Journal of Theoretical Biology, 409, 97-107. doi: 10.1016/j.jtbi.2016.08.035
One of the most well-known models to characterize cooperation among unrelated individuals is Social dilemma (SD). However there is no consensus about how to solve the SD by itself. Since SDs are often embedded in other social interactions, including indirect reciprocity games (IR), human can coordinate their behaviors across multiple games. Such coordination is called ‘linkage’. Recently linkage has been considered as a promising solution to resolve SDs, since excluding SD defectors (i.e. those who defected in SD) from indirectly reciprocal relationships functions as a costless sanction. A previous study performed mathematical modeling and revealed that a linkage strategy, which cooperates in SD and engages in the Standing strategy in IR based on the recipients’ behaviors in both SD and IR, was an ESS against a non-linkage strategy which defects in SD and engages in the Standing strategy in IR based on recipients’ behaviors only in IR (Panchanathan and Boyd, 2004). In order to investigate the robustness of the linkage strategy, we devised a non-linkage strategy, which cooperates in SD but does not link two games. First, we conducted a mathematical analysis and demonstrated that the linkage strategy was not an ESS against cooperating non-linkage strategy. Second, we conducted a series of agent-based computer simulations to examine how the strategies perform in situations in which various types of errors can occur. Our results showed that the linkage strategy was an ESS only when there are implementation errors in SD. However, the equilibrium of the linkage strategy was unstable when there are perception errors. Since we know that humans are not free from perception errors in their social life, future studies will need to show how perception errors can be overcome in order to provide support for the conclusion that linkage is a plausible solution to SDs.
Ishii, K. (石井敬子), Eisen, C. (カリス・アイゼン), & Hitokoto, H. (一言英文) (2017). The effects of social status and culture on delay discounting. 遅延割引における社会的地位と文化の効果 Japanese Psychological Research. doi: 10.1111/jpr.12154
People generally tend to discount future outcomes in favor of smaller but immediate gains (i.e., delay discounting). This study examines the hypothesis that culture and social status moderate this tendency, as well as the alternative hypothesis that social status and culture influence delay discounting independently of each other. American and Japanese adults were asked to choose receiving hypothetical monetary rewards either immediately or receiving rewards of different amounts with a delay of 1 year. The results replicated previous findings and supported the alternative hypothesis. Delay discounting was lower when subjective socioeconomic status (i.e., an individual’s perception of her or his social rank) was higher. Also, the Japanese were less likely to discount future rewards than the Americans. However, there was no interaction between social status and culture in influencing the rates of delay discounting.
Kito, M. (鬼頭美江), Yuki, M. (結城雅樹), & Thomson, R. (トムソン ロバート ジョン) (2017). Relational mobility and close relationships: A socioecological approach to explain cross-cultural differences. 関係流動性と対人関係：社会生態学的アプローチを用いた文化差の説明 Personal Relationships, 24, 114-130. doi: 10.1111/pere.12174
This article reviews how behaviors and psychological tendencies in close relationships differ between cultures, and proposes a socioecological framework to understand those differences. Our review of the literature finds that paradoxically, people in individualistic cultures are more actively engaged in close relationships (e.g., higher levels of social support, self-disclosure, intimacy, and love) than those in collectivistic cultures. From an adaptationist perspective, we argue that one reason for these differences is higher levels of relational mobility in individualistic cultures. In societies with high relational mobility, where relationships are relatively more fragile, more active engagement in close relationships helps individuals to impress potential, and retain current, partners. We emphasize the importance of examining socioecologies to better understand close relationships.
親密な対人関係における行動（e.g., ソーシャルサポート、自己開示）や心理過程（e.g., 親密性、愛）に関する比較文化研究のレビューを行い、「集団主義文化」よりも「個人主義文化」の方が、人々が対人関係に積極的に関わることを明らかにしました。文化心理学において意外なこの知見の原因を、高関係流動性社会への適応という観点から説明しています。つまり、「個人主義文化」では、関係流動性が高く、対人関係が解消されやすいため、対人関係に積極的に関わることにより、関係相手を惹きつけやすくなります。対人関係研究において、人々を取り巻く社会環境の影響を考慮する重要性について考察しています。
Kito, M. (鬼頭美江) (2016). Shared and unique prototype features of relationship quality concepts. 対人関係の良好さに関連する概念間で共通するプロトタイプ特徴と概念特有のプロトタイプ特徴 Personal Relationships, 23, 759-786. doi: 10.1111/pere.12156
Previous research on relationship quality concepts suggests they are not as distinct as expected. What aspects are similar and distinct across these concepts? Using a prototype approach, this research identified the commonalities and uniqueness of 7 relationship quality concepts: commitment, intimacy, love, passion, satisfaction, trust, and relationship quality. The results indicated that (a) 4 features were shared across all 7 concepts, and some were exclusive to each concept, and (b) shared features were rated as more important for romantic relationship functioning than unique features both explicitly and implicitly. This research provides a framework to understand overarching and distinct aspects of relationship quality concepts and how this is reflected in people’s evaluation of what is important in romantic relationships.
Morinaga, Y.（森永康子）, Sakamoto, Y., & Nakashima, K.（中島健一郎） (2017). Gender, Attitudes Toward War, and Masculinities in Japan. （日本におけるジェンダー，戦争に対する態度，そして男らしさ） Psychological Reports. doi: 10.1177/0033294117698463
Previous studies have argued that masculinity is linked to war. We conducted a web-based survey to examine relationships between gender, attitudes toward war, and masculinities within a sample of Japanese adults of both sexes (N = 366). Our results indicated that while men were more likely than women to accept war, the relationship between attitudes toward war and masculinities was inconclusive. Moreover, the results suggested that favorable attitudes toward war among men could be attenuated by interpersonal orientations. Based on our findings, we recommend a reexamination of attitudes toward war within the Japanese population.
Yamamoto, H.(山本仁志), Okada, I., Uchida, S., & Sasaki, T. (2017). A norm knockout method on indirect reciprocity to reveal indispensable norms. 規範ノックアウト手法による協力の進化のための必須規範の解明 Scientific Reports, 7, 44146. doi: 10.1038/srep44146
Although various norms for reciprocity-based cooperation have been suggested that are evolutionarily stable against invasion from free riders, the process of alternation of norms and the role of diversified norms remain unclear in the evolution of cooperation. We clarify the co-evolutionary dynamics of norms and cooperation in indirect reciprocity and also identify the indispensable norms for the evolution of cooperation. Inspired by the gene knockout method, a genetic engineering technique, we developed the norm knockout method and clarified the norms necessary for the establishment of cooperation. The results of numerical investigations revealed that the majority of norms gradually transitioned to tolerant norms after defectors are eliminated by strict norms. Furthermore, no cooperation emerges when specific norms that are intolerant to defectors are knocked out.
Toyokawa, W. （豊川航）(2017). Scrounging by foragers can resolve the paradox of enrichment. 捕食者による略奪行動が生物群集における富栄養化のパラドクスを解消する Royal Society Open Science, 4: 160830. doi:10.1098/rsos.160830
Intuition and experimental evidence suggests that increases in prey availability lead to increases in predator populations. However, theoretical models paradoxically suggest that increased prey can lead to instability in the predator-prey ecosystem and possible extinction. To resolve this paradox, I considered social interactions between predators. Some predators produce (find their own prey) and others scrounge (join in on their companions’ prey). I showed mathematically that when scrounging is prevalent, the ecosystem becomes stable and hence, the paradox disappears. My results highlight the importance of social interactions within group-living animals in maintaining stability of ecological communities.
Ishii, K. (石井敬子), Matsunaga, M., Noguchi, Y., Yamasue, H. Ochi, M. (越智美早), & Ohtsubo, Y. (大坪庸介) (2017) . A polymorphism of serotonin 2A receptor (5-HT2AR) influences delay discounting. セロトニン2A受容体が遅延割引に影響する Personality and Individual Differences. doi: 10.1016/j.paid.2017.03.011
The present study investigated the association between a polymorphism of the serotonin 2A receptor (5-HT2AR) gene and the form of impulsive choice known as delay discounting. Using a hypothetical situation, we asked Japanese participants to choose between receiving (or paying) a different amount of money immediately or with a specified delay (one week, two weeks, one month, six months, one year, five years, or 25 years), and estimated the parameters of intertemporal choice models (exponential, hyperbolic, hyperbolic with exponent, and quasi-hyperbolic). Regardless of the genotypes, the hyperbolic with exponent model, which always indicated minimum AICc (Akaike Information Criterion with small sample correction), fitted better the observed data than the other models. Future gains were discounted more steeply than future losses. Moreover, as expected, individuals with the AA genotype of the 5-HT2AR A-1438G polymorphism discounted the future more steeply than did individuals with the GG genotype, although this effect was limited to only gains. The findings implied individual differences based on the A-1438G polymorphism in the modulation of serotonin in the reward valuation underlying delay discounting.
Johnson, B., & Nakayachi, K. (中谷内 一也) (2017). Examining Associations Between Citizens' Beliefs and Attitudes about Uncertainty and Their Earthquake Risk Judgments, Preparedness Intentions, and Mitigation Policy Support in Japan and the United States. 日米における地震についての不確実性とリスク判断、準備意図、被害軽減政策支持などについての市民の信念と態度の関連性 International Journal of Disaster Risk Reduction, 22, 37–45. doi: 10.1016/j.ijdrr.2017.02.019
Although hazards are inherently uncertain, research on citizens’ judgments of risk, hazard preparedness, and support for mitigation policies has rarely accounted for citizens’ beliefs about the uncertainty of fields estimating hazard risk or in science as providing accurate, unbiased knowledge, nor citizens’ need to achieve quick, certain answers. Parallel online surveys of residents of earthquake-prone areas of Japan and the United States revealed that belief in scientific positivism increased policy support in both countries (as did need for closure among Americans), and belief in seismological uncertainty reduced judged earthquake risk in Japan, with small effect sizes. Preparedness was unaffected by these predictors. Associations of other factors (quake experience; trust in experts; demographics) with dependent variables were consistent with other studies, and Japanese-American differences were small on dependent variables and in most predictors. Motivation (i.e., high involvement with the topic, relevance of the fictional earthquake rupture forecast in a quasi-experiment embedded in the survey, and judged ability to use its information) strongly affected judged risk, preparedness and policy support. Low-motivation Japanese and high-motivation Americans exhibited associations most similar to overall findings for their nations. Implications of these findings for hazards research and risk communication are discussed.
Miyatake, S.(宮武沙苗), & Higuchi, M.(樋口匡貴) (2017). Does religious priming increase the prosocial behaviour of a Japanese sample in an anonymous economic game? 宗教プライミングは向社会的行動を増加させるか？匿名の経済ゲームを用いた日本人サンプルによる検討 Asian Journal of Social Psychology. doi: 10.1111/ajsp.12164
We examined the effect of religious priming on a Japanese sample in an anonymous dictator game whereas previous studies on religious priming on prosociality had mainly been conducted within Western contexts. The current study attempted to examine whether religion increases prosocial behaviour in a Japanese sample through the replication of ‘God is Watching You’ (Shariff & Norenzayan, 2007) where it was found that participants primed with religion-related words and secular justice-related words behaved more prosocially than participants primed with neutral words in an anonymous dictator game. The current experiment was conducted with Japanese students (n = 106) to examine whether the results of the original study could be applied to Japanese people. The results showed that among the three priming conditions (control, religion, secular justice), there was no difference in the amount of money participants allocated to anonymous strangers, although in the secular justice priming condition, theists allocated more money than atheists. The results might be due to the fact that the religious priming words used in the original study did not precisely activate the propositional network of religion that Japanese participants have. More culture-specific studies are necessary to examine how religious priming works for non-Westerners.
Uchida, Y.（内田由紀子）, Savani, K., Hitokoto, H. (一言英文), & Kaino K. (2017). Do You Always Choose What You Like? Subtle Social Cues Increase Preference-Choice Consistency among Japanese But Not among Americans. （微細な社会的手がかりが選好選択の一貫性に及ぼす影響の日米比較） Frontiers in Psychology. doi: 10.3389/fpsyg.2017.00169
Previous research has suggested that stability of self-concept differs across cultures: in North American cultural contexts, people’s self-concept is stable across social contexts, whereas in Japan, different self-concepts are activated within specific social contexts. We examined the implications of this cultural difference for preference-choice consistency, which is people’s tendency to make choices that are consistent with their preferences. We found that Japanese were less likely than Americans to choose items that they liked the most, showing preference-choice inconsistency. We also investigated the conditions in which Japanese might exhibit greater preference-choice consistency. Consistent with research showing that in Japanese culture, the self is primarily conceptualized and activated by social contexts, we found that subtle social cues (e.g., schematic representations of human faces) increased preference-choice consistency among Japanese, but not among Americans. These findings highlight that choices do not reveal preferences to the same extent in all cultures, and that the extent to which choices reveal preferences depends on the social context.
Yanagisawa, K.（柳澤邦昭）, Kashima. E. S., Moriya. H., Masui, K.（増井啓太）, Furutani, K.（古谷嘉一郎）, Yoshida, H., Ura, M.（浦光博）, & Nomura, M.（野村理朗） (2017). Tolerating dissimilar other when primed with death: Neural evidence of self-control engaged by interdependent people in Japan. 死をプライムされたとき、価値観の異なる他者を受け入れる： 相互協調的自己観の高い日本人のセルフコントロールに関する神経科学的知見 Social Cognitive and Affective Neuroscience. doi: 10.1093/scan/nsx012
Mortality salience (MS) has been shown to lead to derogation of others with dissimilar worldviews, yet recent research has shown that Asian-Americans who presumably adopt an interdependent self-construal (SC) tend to reveal greater tolerance after MS induction. In the present study, we demonstrated that Japanese individuals who are high on interdependent SC indeed show greater tolerance towards worldview-threatening other in the MS (vs. control) condition, thus replicating the prior research. Extending this research, we also found that interdependent people’s tolerance towards worldview-threatening other was mediated by increased activity in the right ventrolateral prefrontal cortex (rVLPFC) in the MS condition. These data suggested that when exposed to death-related stimuli, highly interdependent individuals may spontaneously activate their neural self-control system which may serve to increase tolerance towards others.
Tsuboya, T., Aida, J., Hikichi, H.（引地博之）, Subramanian S., Kondo K., Osaka, K., & Kawachi, I. (2017). Predictors of decline in IADL functioning among older survivors following the Great East Japan earthquake: A prospective study. 東日本大震災被災高齢者の手段的日常生活動作低下の予測要因：前向き研究の結果から Social Science & Medicine, 176, 34–41. doi: 10.1016/j.socscimed.2016.05.026
We described associations between the type of disaster experience and change in instrumental activities of daily living among older adult survivors before-after a terrible disaster.
The study took advantage of a “natural experiment” afforded by the Japan Gerontological Evaluation Study (JAGES), a nationwide cohort study established in 2010, seven months prior to the earthquake and tsunami. A follow-up survey was conducted in 2013. This study was conducted in Iwanuma, which was directly struck by tsunami. Our sample comprised community-dwelling aged survivors in Iwanuma who responded to questions about personal circumstances and functional status both before and after the disaster (N = 3547). Personal experiences of earthquake and tsunami damage was used as an exposure variable. The outcome was changes in self-reported 13-item instrumental activities of daily living (IADL), which was assessed both before and after the disaster.
Among the participants, 931 reported losing family member(s) to the disaster, while a further 549 reported losing friend(s). More than half of the participants reported any damage to their houses while approximately 1 in 8 lost their car(s). The multivariable OLS regression revealed that complete house loss and disruption of internal medicine were associated with significantly worse IADL: −0.67 points (95%CI: −0.99, −0.34) for entirely destroyed homes; −0.40 points (95% CI: −0.71, −0.092) for disruption of internal medicine. By contrast, loss of family/friends/pets/cars and disruption to the other medical service were not associated with decline in IADL.
Complete house loss and disruption of access to internal medicine after a disaster were associated with significant adverse impact on decline in physical and cognitive functions 2.5 years after the disaster, while loss of family/friends was not.
Hikichi, H.（引地博之）, Kondo, K., Takeda, T., & Kawachi, I. (2016). Social interaction and cognitive decline: Results of a 7-year community intervention 社会的交流と認知機能の関連：７年間のコミュニティ介入研究の結果から Alzheimer's & Dementia: Translational Research & Clinical Interventions. doi: 10.1016/j.trci.2016.11.003
There are few intervention studies that demonstrated linking social participation to lower risk of cognitive decline. We examined prospectively the protective effect of a community intervention program promoting social participation on the incidence of cognitive disability.
The baseline was established in a survey of community-dwelling older people aged 65 years old or more in July 2006 (2793 respondents, response rate 48.5%). The setting was Taketoyo town in Japan, where municipal authorities launched an intervention that was based on the establishment of community-based centers called “salons,” where the town’s senior residents could congregate and participate in social activities, ranging from arts and crafts, games, and interactive activities with preschool children. Three salons were established in May 2010, and a total of 10 salons were in operation by 2013. We recorded the frequency of salon participation among survey respondents till 2013 and conducted two follow-up surveys (in 2010 and 2013) to collect information about health status and behaviors. The onset of cognitive disability was followed from May 2007 to January 2014. We used the marginal structural models to evaluate the effect of program.
The range of prevalence of cognitive disability was from 0.2% to 2.5% during the observation period. The proportion of respondents who participates to salons increased over time to about 11.7%. The frequency of salon participation was protectively associated with cognitive decline, even after adjusting for time-dependent covariates and attrition (odds ratio = 0.73, 95% confidence interval: 0.54–0.99).
Our study suggests that operating community salons that encourage social interactions, light physical activity, and cognitive activities among older participants may be effective for preventing cognitive decline. In future studies, we need to understand what sorts of activities (e.g., those involving light physical activity vs. purely intellectual activities) are most effective in maintaining cognitive function.
Mifune, N.(三船恒裕), Simunovic, D., & Yamagishi, T.(山岸俊男) (2017). Intergroup Biases in Fear-induced Aggression. 恐怖性攻撃行動における集団間バイアス Frontiers in Psychology. doi: 10.3389/fpsyg.2017.00049
Using a recently created preemptive strike game (PSG) with 176 participants, we investigated if the motivations of spite and/or fear promotes aggression that requires a small cost to the aggressor and imposes a larger cost on the opponent, and confirmed the earlier finding that fear does but spite does not promote intergroup aggression when the groups are characterized as minimal groups; additionally, the rate of intergroup aggression did not vary according to the group membership of the opponent. The PSG represents a situation in which both the motivations of spite and of fear can logically drive players to choose an option of aggression against an opponent. Participants decide whether or not to attack another participant, who also has the same capability. The decision is made in real time, using a computer. We discuss theoretical implications of our findings on the evolutionary foundations of intragroup cooperation and intergroup aggression. The evolutionary model of intergroup aggression, or the parochial altruism model, posits that intragroup cooperation and intergroup aggression have co-evolved, and thus it predicts both intragroup cooperation and intergroup aggression to emerge even in a minimal group devoid of a history of intergroup relationships. The finding that only intragroup cooperation but not intergroup aggression emerged in the minimal group experiments strongly suggests that intergroup aggression involves a psychological mechanism that is independent from that of intragroup cooperation. We further discuss the implications of these findings on real-world politics and military strategy.
Horita, Y. (堀田結孝), Takezawa, M. (竹澤正哲), Inukai, K.（犬飼佳吾）, Kita, T. (喜多敏正), & Masuda, N. (2017). Reinforcement learning accounts for moody conditional cooperation behavior: experimental results. 強化学習は気分的条件付き協力行動を説明する：実験研究 Scientific Reports, 7, 39275. doi:10.1038/srep39275
In social dilemma games, human participants often show conditional cooperation (CC) behavior or its variant called moody conditional cooperation (MCC), with which they basically tend to cooperate when many other peers have previously cooperated. Recent computational studies showed that CC and MCC behavioral patterns could be explained by reinforcement learning. In the present study, we use a repeated multiplayer prisoner’s dilemma game and the repeated public goods game played by human participants to examine whether MCC is observed across different types of game and the possibility that reinforcement learning explains observed behavior. We observed MCC behavior in both games, but the MCC that we observed was different from that observed in the past experiments. In the present study, whether or not a focal participant cooperated previously affected the overall level of cooperation, instead of changing the tendency of cooperation in response to cooperation of other participants in the previous time step. We found that, across different conditions, reinforcement learning models were approximately as accurate as a MCC model in describing the experimental results. Consistent with the previous computational studies, the present results suggest that reinforcement learning may be a major proximate mechanism governing MCC behavior.
Shibuya, A.（渋谷明子）, Teramoto, M.（寺本水羽）, & Shoun, A.（祥雲暁代） (2016). Toward Individualistic Cooperative Play: A Systematic Analysis of Mobile Social Games in Japan. 日本のモバイルソーシャルゲームの社会的要素について系統的分析を行い、個人プレイだが、協力要素があるゲームが多い点などを指摘 In Dal Yong Jin (ed). Mobile Gaming in Asia: Politics, Culture and Emerging Technologies (Part of the series Mobile Communication in Asia: Local Insights, Global Implications). pp 207-225. ISBN: 978-94-024-0824-9 (Print) 978-94-024-0826-3 (Online)
This study examines the social features of the 31 most popular games in Japan’s rapidly expanding mobile social game market, as ranked through a survey of 2660 teenagers and young adults in November 2013. Results showed that all 31 games had at least one of the three social features, namely, connections to social networking services (SNSs), competition, and cooperation. In the games, SNS connections were present in 84 % of games, competition in 87 % of games, cooperation in 94 %. Among the cooperative features, individualistic cooperative play was more prevalent than team play. Keywords：Smartphones Social features Social games Systematic analysis Mobile device.