The etiology of human same-sex romantic attraction is generally framed in terms of (1) social influences, (2) genetic influences, or (3) hormonal influences. In this article, we show that adolescent males who are opposite-sex twins are twice as likely as expected to report same-sex attraction; and that the pattern of concordance (similarity across pairs) of same-sex preference for sibling pairs...

The purpose of the study was to test four predictions derived from evolutionary (sexual strategies) theory. The central hypothesis was that men and women possess different emotional mechanisms that motivate and evaluate sexual activities. Consequently, even when women express indifference to emotional involvement and commitment and voluntarily engage in casual sexual relations, their goals, the...

in general, sexual behavior shapes in the depth of society and culture and social and cultural expectations influence to a great extent. also sexual relations in iran, take place outside of marriage with different reasons and in different forms. some evidences imply an increasing trend of this style of life among young people, accordingly, this study wants to analyze this phenomenon and achieve...

Sexual harassment and coercion have mainly been considered from a sex difference perspective. While traditional social science theories have explained harassment as male dominance of females, the evolutionary perspective has suggested that sex differences in the desire for sex are a better explanation. This study attempts to address individual differences associated with harassment from an evol...