Supporting Information
Figure S1  Distribution of trust behaviors and plasma oxytocin. (A) Distribution of the amount sent by the first player; (B) Distribution of the average amount returned by the second player; (C) Distribution of level of oxytocin; (D) Distribution of log level of oxytocin without outliers.
(PDF) Click here for additional data file.   Figure S2  Gender Difference. (A) Level of trust of male and female; (B) Level of trustworthiness of male and female; (C) Level of OT of male and female.
(PDF) Click here for additional data file.