Figure 1.

Testing timeline. Male subjects were primed for pairbonding on day 1. On day 6, subjects underwent the first pair interaction test in which both groups received a saline injection. On day 8, subjects were tested in a second pair interaction test after either a saline injection (saline group) or a testosterone injection (T group). On day 13, subjects underwent the first resident-intruder test in which both groups received a saline injection. On day 15, subjects were tested in a second resident-intruder test after either a saline injection (saline group) or a T injection (T group). On day 21, subjects were perfused immediately after an IEG test where subjects interacted with their pairbond partner.