The most accepted explanation for gender differences is the sociocultural model that holds them to be results of socialization and/or occupancy of sex differentiated roles. There has been extensive social change in the past three decades, reducing sex typed role assignments and attitudes. However, examination of some 30 researches shows that the social change has not been followed by change in sex typing. This present study of trends in stereotypic and self responses between 1974 and 1997 confirms the stability in sex typing, over seven surveys and 4,000 respondents. In addition, there is evidence of increase in the perceived femininity of females. These results are contrary to the predictions from the sociocultural model. They are, however, consistent with the alternate evolutionary model postulating constant gendered differences based on genetic patterns evolved from adaptations to differing reproductive challenges of early males and females.