Researchers at the University of Michigan and Albright College in Pennsylvania conducted anonymous online surveys that have refuted commonly-held beliefs regarding partner behaviour after sex. Self-reports from 456 participants revealed that those whose partners tended to fall asleep first after sex had stronger preferences for post-coital bonding time. Contrary to popular belief, the study showed that men were not more likely to fall asleep first after sex. Instead, both males and females had equal tendencies towards this behaviour. It has been suggested that falling asleep first might be a method of avoiding relationship-focused conversation. In contrast, staying awake longer might be a behavioural trait that has evolved from the desire to ensure that partners did not seek other mates. The scientists added that, while the majority of psychological and evolutionary research on reproductive strategies currently focuses on pre-coital topics such as mate selection, postcoital behaviour is just as important and reveals much about partner satisfaction and relationship commitment.
