国際誌論文データベース

Fujii, T.（藤井貴之）, Schug, J.（ジョアンナ・シューグ）, Nishina, K.（仁科国之）, Takahashi, T., Okada, H., & Takagishi, H.（高岸治人）(2016).
Relationship between Salivary Oxytocin Levels and Generosity in Preschoolers.
未就学児における唾液中オキシトシンレベルと気前良さの関係
Scientific Reports, 6: 38662 
doi: 10.1038/srep38662

This study examined the association between salivary oxytocin (sOT) levels and generosity in preschoolers. Fifty preschoolers played two dictator games (DG) by deciding how to allocate 10 chocolates between themselves and another child, who was either from the same class as the participant (ingroup member), or an unknown child from another class (outgroup member). sOT levels were assessed in saliva collected from the children immediately prior to the DG tasks. While sOT levels were negatively associated with allocations made to both ingroup and outgroup members by boys, among girl sOT levels were positively related to allocations made to ingroup members, and unrelated to allocations made to outgroup members. These results suggest sex differences in the association between salivary oxytocin and generosity.

Toyokawa, W.（豊川航）, Saito, Y.（斎藤美松）, & Kameda, T.(亀田達也) (2016).
Individual differences in learning behaviours in humans: asocial exploration tendency does not predict reliance on social learning
（学習行動の個人差: 単独課題での探索傾向は、集団課題での社会情報利用を予測しない）
Evolution & Human Behavior.
doi: 10.1016/j.evolhumbehav.2016.11.001

A number of empirical studies have suggested that individual differences in asocial exploration tendencies in animals may be related to those in social information use. However, because the ‘exploration tendency’ in most previous studies has been measured without considering the information-gathering processes, it is yet hard to conclude that the animal asocial exploration strategies may be tied to social information use. Here, we studied human learning behaviour in both asocial and social two-armed bandit tasks. By fitting reinforcement learning models including asocial and/or social decision processes, we measured each individual’s (1) asocial exploration tendency and (2) social information use. We found consistent individual differences in the exploration tendency in the asocial tasks. We also found substantive heterogeneity in the adopted learning strategies in the social task: Nearly one-third of participants used predominantly the copy-when-uncertain strategy, while the remaining two-thirds were most likely to have relied only on asocial learning. However, we found no significant individual association between the exploration frequency in the asocial task and the use of the social information in the social task. Our results suggest that the social learning strategies may be independent from the asocial exploration strategies in humans.

Kobayashi, T.(小林哲郎), Miura, A.(三浦麻子), & Inamasu, K.(稲増一憲) (2017). 
Media priming effect: A preregistered replication experiment. 
（メディアのプライミング効果：プレレジストレーションを伴う再現可能性検証実験）
Journal of Experimental Political Science, 4(1), 81-94.

Iyengar et al. (1984) discovered the media priming effect, positing that by drawing attention to certain issues while ignoring others, television news programs help define the standards by which presidents are evaluated. We conducted a direct replication of Experiment 1 by Iyengar et al. (1984), with some changes. Specifically, we (a) collected data from Japanese undergraduates; (b) reduced the number of conditions to two; (c) used news coverage of the issue of relocating US bases in Okinawa as the treatment; (d) measured issue-specific evaluations of the Japanese Prime Minister in the pretreatment questionnaire; and (e) performed statistical analyses that are more appropriate for testing heterogeneity in the treatment effect. We did not find statistically significant evidence of media priming. Overall, the results suggest that the effects of media priming may be quite sensitive either to the media environment or to differences in populations in which the effect has been examined. [Preregistration(OSF)] メディアのプライミング効果（メディアが報道するニュースは，議題設定機能を果たすだけでなく，受け手（一般市民）がどの政治的争点が重要かを判断するかを判断する際の基準の形成にも影響を与える）を実証した研究としてしばしば引用されるIyengar, Kinder, Peters, and Krosnick (1984)の実験1を追試したものです．結果はNullでした．

Hikichi, H. (引地博之), AIda, J., Kondo, K., Tsuboya, T., Matsuyama, Y., Suburamanian, S. V., & Kawachi, I. (2016).
Increased risk of dementia in the aftermath of the 2011 Great East Japan Earthquake and Tsunami
東日本大震災における被災経験と認知症リスクの関連
Proceedings of the National Academy of Sciences of the United States of America. 
doi: 10.1073/pnas.1607793113.

No previous study has been able to examine the association by taking account of risk factors for dementia before and after the disaster. We prospectively examined whether experiences of a disaster were associated with cognitive decline in the aftermath of the 2011 Great East Japan Earthquake and Tsunami. The baseline for our natural experiment was established in a survey of older community-dwelling adults who lived 80 km west of the epicenter 7 mo before the earthquake and tsunami. Approximately 2.5 y after the disaster, the follow-up survey gathered information about personal experiences of disaster as well as incidence of dementia from 3,594 survivors (82.1% follow-up rate). Our primary outcome was dementia diagnosis ascertained by in-home assessment during the follow-up period. Among our analytic sample (n = 3,566), 38.0% reported losing relatives or friends in the disaster, and 58.9% reported property damage. Fixed-effects regression indicated that major housing damage and home destroyed were associated with cognitive decline: regression coefficient for levels of dementia symptoms = 0.12, 95% confidence interval (CI): 0.01 to 0.23 and coefficient = 0.29, 95% CI: 0.17 to 0.40, respectively. The effect size of destroyed home is comparable to the impact of incident stroke (coefficient = 0.24, 95% CI: 0.11 to 0.36). The association between housing damage and cognitive decline remained statistically significant in the instrumental variable analysis. Housing damage appears to be an important risk factor for cognitive decline among older survivors in natural disasters.

Oshio, A.(小塩真司), Mieda, T., Taku, K. (2016)
 Younger people, and stronger effects of all-or-nothing thoughts on aggression: 
 Moderating effects of age on the relationships between dichotomous thinking and aggression.
 二分法的思考と攻撃性の関係を年齢が仲介する（若年ほど効果が強い）
 Cogent Psychology, 3(1).
 doi: 10.1080/23311908.2016.1244874

Binary or dichotomous thinking may lead to aggression throughout people’s lifespan; additionally, relationships are likely to be affected by types of aggression (i.e. physical aggression, verbal aggression, anger, and hostility) as well as gender and age. Using large-scale data (N = 2,315), the current study tested if age or gender moderated dichotomous thinking’s correlation with four different types of aggression. Participants (Mage = 36.1, SD = 16.2, range = 18–69) completed the Dichotomous Thinking Inventory and the Buss-Perry Aggression Questionnaire. Dichotomous thinking differentially affected aggression depending on participants’ age: dichotomous thinking and aggression were more strongly correlated in younger participants. Individuals’ tendency to think dichotomously appeared relatively stable; however, age appeared to moderate dichotomous thinking’s effects.

Ishii, K. (石井健一)　(2017).
 Online communication with strong ties and subjective well-being in Japan.
 日本人の幸福感と強い紐帯とのオンラインコミュニケーション
 Computers in Human Behavior, 66, 129–137.
 doi: 10.1016/j.chb.2016.09.033

Recent developments in communication technologies have changed how people connect and interact with each other. This study investigates whether and how online communication with strong ties (mobile phone and social networking service [SNS]) enhances subjective well-being in Japan. Study 1 examined whether the correlation between happiness and mobile phone use was mediated by the number of offline and online friends. Study 2 assessed the associations between the Japanese relationship-oriented value “interdependent self-view,” life satisfaction, and the use of SNS. Results indicate that only the use of LINE (an instant messaging application), which is the most popular SNS in Japan, was significantly correlated with life satisfaction and interdependent self-view. The number of friends (offline and online) mediated the effect of LINE use on life satisfaction. Interdependent self-view was significantly correlated with the frequency of LINE use, homogeneity of LINE friends, and life satisfaction. These results indicate that the use of a dominant online communication method with strong ties is significantly correlated with subjective well-being, and this significant correlation is mediated by the number of offline and online friends.

Niiya, Y.（新谷優） (2016). 
Does a favor request increase liking toward the requester?
頼み事をされるとその人への好意は増すか？
Journal of Social Psychology, 156(2), 211-221.
doi: 10.1080/00224545.2015.1095706

Although a request for help can impose a burden on the provider and has the potential of harming a relationship, the theory of amae suggests that in fact it could help promote a stronger relationship. In an experiment, both Japanese and American participants who were asked for help from a confederate increased their liking of the confederate relative to the baseline. Sociable impression of the confederate and perceived closeness of the relationship also increased relative to the baseline. There was, however, no such increase when participants helped the confederate without receiving a direct request. This study suggests that despite the potential risks to relationships, asking favors can provide opportunities for requesters to build and promote relationships.

Ogihara, Y. (荻原祐二). (2016). 
The Change in Self-Esteem among Middle School Students in Japan, 1989-2002. 
1989年から2002年の日本の中学生における自尊感情の経時的変化 
Psychology, 7, 1343-1351. 
doi: 10.4236/psych.2016.711136

This paper examined temporal changes in self-esteem among middle school students in Japan from 1989 to 2002. Previous research showed that self-esteem decreased among middle school students between 1999 and 2006. However, it was unclear whether such a decrease was also present in other periods of time. To obtain a better understanding of how people adapt to socio-economic environments, it is important to gain a more comprehensive view of such long-term cultural/social changes. Therefore, to supplement the findings of the existing research on changes in self-esteem, we analyzed large-sample time-series data collected in Japan in 1989 and 2002. We found that middle schoolers’ self-esteem decreased from 1989 to 2002, consistent with previous research. Thus, our study extends the previous research by presenting additional data showing the decrease in self-esteem in Japan.

関連論文(Previous research)：Ogihara, Uchida, & Kusumi (2016)

Matsumoto, Y.(松本良恵), Yamagishi, T.(山岸俊男), Li, Y.(李楊), & Kiyonari, T.(清成透子) (2016).
Prosocial Behavior Increases with Age across Five Economic Games.
（向社会的行動は年齢と共に増加する：5つの経済ゲームによる検討）
PLoS ONE. 
doi: 10.1371/journal.pone.0158671

Ontogenic studies of human prosociality generally agree on that human prosociality increases from early childhood through early adulthood; however, it has not been established if prosociality increases beyond early adulthood. We examined a sample of 408 non-student residents from Tokyo, Japan, who were evenly distributed across age (20–59) and sex. Participants played five economic games each separated by a few months. We demonstrated that prosocial behavior increased with age beyond early adulthood and this effect was shown across all five economic games. A similar, but weaker, age-related trend was found in one of three social value orientation measures of prosocial preferences. We measured participants’ belief that manipulating others is a wise strategy for social success, and found that this belief declined with age. Participants’ satisfaction with the unilateral exploitation outcome of the prisoner’s dilemma games also declined with age. These two factors—satisfaction with the DC outcome in the prisoner’s dilemma games and belief in manipulation—mediated the age effect on both attitudinal and behavioral prosociality. Participants’ age-related socio-demographic traits such as marriage, having children, and owning a house weakly mediated the age effect on prosociality through their relationships with satisfaction with the DC outcome and belief in manipulation.

Yamagishi, T.(山岸俊男), Li, Y.(李楊), Matsumoto, Y.(松本良恵), Kiyonari, T.(清成透子) (2016)
Moral Bargain Hunters Purchase Moral Righteousness When it is Cheap: Within-Individual Effect of Stake Size in Economic Games.
（モラルバーゲンハンターはモラルの正しさを購買する．ただし，安ければ：経済ゲームにおける個人内ステイクサイズの効果）
Scientific Reports, 6: 27824.
doi: 10.1038/srep27824

Despite the repeatedly raised criticism that findings in economic games are specific to situations involving trivial incentives, most studies that have examined the stake-size effect have failed to find a strong effect. Using three prisoner’s dilemma experiments, involving 479 non-student residents of suburban Tokyo and 162 students, we show here that stake size strongly affects a player’s cooperation choices in prisoner’s dilemma games when stake size is manipulated within each individual such that each player faces different stake sizes. Participants cooperated at a higher rate when stakes were lower than when they were higher, regardless of the absolute stake size. These findings suggest that participants were ‘moral bargain hunters’ who purchased moral righteousness at a low price when they were provided with a ‘price list’ of prosocial behaviours. In addition, the moral bargain hunters who cooperated at a lower stake but not at a higher stake did not cooperate in a single-stake one-shot game. 玉川大学プレスリリース