Kurokawa Hirofumi, Kinari Yusuke, Okudaira Hiroko, Tsubouchi Kiyotaka, Sai Yoshimichi, Kikuchi Mitsuru, Higashida Haruhiro, Ohtake Fumio
School of Economics and Management, University of Hyogo, Kobe, Japan.
Hirao School of Management, Konan University, Nishinomiya, Japan.
Front Neurosci. 2021 May 25;15:659737. doi: 10.3389/fnins.2021.659737. eCollection 2021.
There have been numerous studies in which the biological role of oxytocin in trusting behavior has been investigated. However, a link between oxytocin and trust in humans was discovered only in one early study. We hypothesized that there is a large interindividual variation in oxytocin sensitivity, and that such variation is one reason for the doubt surrounding the role of oxytocin in trusting behavior. Here, in a double-blind, prospective, case-control study, we administered intranasal oxytocin to participants of trust and risk games. We measured salivary oxytocin concentration, relating it to the amount of money transferred among participants (a proxy for trust) and the autism-spectrum quotient (AQ). A one-sided Fisher's exact test was performed to detect differences between the oxytocin and placebo groups in the proportions of investors who transferred the maximum amount of money. We discovered a tendency for participants who received oxytocin to transfer higher amounts of money to co-participants than those who received a placebo ( = 0.04). We also revealed a high degree of interindividual variation in salivary oxytocin concentrations after oxytocin administration. After stratifying the samples with respect to oxytocin sensitivity, oxytocin-sensitive participants in the oxytocin group also transferred higher amounts of money than those in the placebo group ( = 0.03), while such a tendency was not observed for oxytocin-insensitive participants ( = 0.34). Participants with lower AQ scores (less severe autistic traits) exhibited a greater tendency toward trusting behavior after oxytocin administration than did those with higher AQ scores ( = 0.02). A two-sample -test that was performed to detect significant differences in the mean transfers between the oxytocin and placebo groups indicated no significant between-group difference in the mean transfers ( = 0.08). There are two possible interpretations of these results: First, there is no effect of oxytocin on trust in humans; second, the effects of oxytocin on trust in humans is person-dependent. However, the results should be interpreted with caution as the effect size was not larger than the minimal detectable effect size and the results were not statistically significant ( > 0.05) after Bonferroni corrections.
已有大量研究对催产素在信任行为中的生物学作用进行了调查。然而，催产素与人类信任之间的联系仅在一项早期研究中被发现。我们推测，催产素敏感性存在很大的个体差异，而这种差异是围绕催产素在信任行为中作用的疑问的一个原因。在此，在一项双盲、前瞻性、病例对照研究中，我们给信任和风险游戏的参与者鼻内注射催产素。我们测量了唾液中催产素的浓度，并将其与参与者之间转移的金钱数量（信任的一个指标）以及自闭症谱系商数（AQ）相关联。进行了单侧费舍尔精确检验，以检测催产素组和安慰剂组中转移最大金额的投资者比例之间的差异。我们发现，接受催产素的参与者比接受安慰剂的参与者有向共同参与者转移更高金额金钱的趋势（P = 0.04）。我们还揭示了注射催产素后唾液中催产素浓度存在高度的个体差异。在根据催产素敏感性对样本进行分层后，催产素组中对催产素敏感的参与者也比安慰剂组的参与者转移了更高金额的金钱（P = 0.03），而对催产素不敏感的参与者未观察到这种趋势（P = 0.34）。AQ分数较低（自闭症特征较轻）的参与者在注射催产素后比AQ分数较高的参与者表现出更大的信任行为倾向（P = 0.02）。为检测催产素组和安慰剂组之间平均转移金额的显著差异而进行的双样本t检验表明，两组之间的平均转移金额没有显著差异（P = 0.08）。这些结果有两种可能的解释：第一，催产素对人类信任没有影响；第二，催产素对人类信任的影响因人而异。然而，这些结果应谨慎解释，因为效应大小不大于最小可检测效应大小，并且在进行邦费罗尼校正后结果无统计学意义（P>0.05）。
