An examination of the organizational and activational effects of oxytocin on some social psychological variables

Perinatal exposures to hormones and similar substances can have relatively long-term differentiation on the organization of newborns' brain structures and subsequent behaviors. Although the organizational effects of sex steroids on sexual behaviors have been frequently demonstrated, it is still unknown whether perinatal hormone exposures have developmental effects on human social behaviors. In addition to the well-known peripheral effects on birth and breastfeeding, the neuropeptide oxytocin (OT) also plays a central role in the regulation of social behavior. Therefore, it is quite possible that some of the individual differences observed in social behavior skills reflect the long-term effects of differences in perinatal OT levels. However, the potential developmental effects of varying levels of perinatal exposure to OT have not been explored. In parallel with the peripheral role of OT in inducing uterine contractions during vaginal delivery, it has been consistently reported that OT levels observed in both the mother and the offspring during spontaneous vaginal delivery are significantly higher compared to planned/elective cesarean delivery where the normal birth process does not initiate. In the light of these findings, the aim of this thesis is to investigate whether there are differences in social behavior skills between adults born via vaginal and planned cesarean delivery. For this purpose, adults who meet various inclusion criteria and were born either through vaginal or planned cesarean delivery were compared in terms of their emotion recognition and empathy skills, which are socio-cognitive variables strongly associated with OT. The Participants' emotion recognition skills were measured through the correct identification rates and the time taken to perceive the facial expressions of six basic emotions in dynamic emotion transition videos created using face morphing technique. Participants' empathy skills were evaluated based on the correct response rates and reaction times obtained from a computerized adaptation of the Reading the Mind in the Eyes Test, which involves predicting the mental states of individuals based on their eye region. The findings indicated that participants born via vaginal delivery had significantly higher accuracy rates in recognizing emotions, compared to those born via planned cesarean section, and this result was observed for all basic emotions except happiness. Similarly, participants born via vaginal delivery had significantly higher correct response rates in the Reading the Mind in the Eyes Test compared to those born via planned cesarean section. In addition to these findings, it was observed that women scored higher than men in terms of accuracy rates in emotion recognition, and certain emotions were recognized more accurately and quickly compared to others. The results suggested that the mode of delivery and the associated levels of perinatal OT may be critical for the optimal development of social behavior skills. The findings and their implications were discussed in the context of relevant literature, and limitations of the study were addressed, along with recommendations for future research. Keywords: Organizational effects of hormones, oxytocin, delivery type, planned cesarean section, social behavior