Part 1 — sex and gender. Furthermore, as O'Brien et al. A theory of gender and health. Thus, variation in preferences for masculine men may reflect choices for more prosocial partners and nurturing fathers over possible indirect and direct benefits associated with masculine facial traits 30 , The primer itself has been downloaded over times by people all around the world who have found it useful for teaching, grant writing, and manuscript preparation purposes. When finished, throw the dam away. Likewise, if someone is sexually active, STI testing should be a regular occurrence. To address this issue, we used Independent Factors Analysis IFA to reduce the 11 of country-level predictors to two factors. Further, it is important to distinguish between the benefits of national prosperity on scholastic achievement of girls on the one hand and the sex differences in scholastic achievement on the other hand. We do recognize that if sex was not a variable in the original data set, that reanalyzing by sex may not be possible. Many of the studies on sex determination in O. Furthermore, there has been speculation that gender roles positively influence the way that men interact with physicians when seeking help for injured knees, and that women's narrative speaking style is not as effective in health care appointment settings as men's factual and to-the-point style [ 57 ]. How were your data collected and how does this affect your results? For example, researchers have found that knee laxity, limb alignment, knee notch dimensions, and ligament size differ between the sexes and all have been theorized to cause women's greater risk of ACL injury [ 52 ]. Random intercepts included participant id, country, and face id, which accounts for the potential non-independence of observations made by the same participant, participants in the same country, and of the same stimuli across participants.