canstockphoto18179008"CHES Faculty Member Lee Cronk and CHES alumni Robert Lynch and Helen Wasielewski recently published a paper “Sexual conflict and the Trivers-Willard hypothesis: Females prefer daughters and males prefer sons” in Nature Scientific Reports. The TW hypothesis predicts that parents who are in good condition will bias investment towards sons, while parents who are in poor condition will bias investment towards daughters. Contrary to the expectations of this hypothesis, the researchers found that the socioeconomic backgrounds of the human participants had no effect on their expressed preferences towards offspring of either sex. Instead, however, Cronk, Lynch, and Wasielewski found that in general women prefer daughters and that men have either a slight preference for sons or no preference at all. These patterns were seen across the four measured variables: 1) explicitly stated preferences; 2) responses to timed “Implicit Association Tests” (which detect attitudes that people may be unwilling or unable to report); 3) donations to charities supporting either boys or girls after an experimental prime and; 4) asking subjects if they would rather adopt a daughter or a son. Cronk and colleagues are planning a follow-up study that uses a new design they think is more sensitive to preferences for sons and daughters as a function of socioeconomic status.