An Evolutionary Psychology Perspective on Sex Differences in Exercise Behaviors and Motivations Peter K. Jonason Summary and presentation by: Redd Davis, Aubrie DeBear & Sam Doyle Jonason, P. K. (2007). An evolutionary psychology perspective on sex differences in exercise behaviors and motivations. The Journal of Social Psychology, 147(1), 5-14.

Hypotheses Men spend more time focusing on upper body development Women will spend more time on lower body development Men spend more time toning and building muscles than women Women spend more time trying to lose weight than men There will be no significant difference in time spent focusing on abdominal exercises Jonason, P. K. (2007). An evolutionary psychology perspective on sex differences in exercise behaviors and motivations. The Journal of Social Psychology, 147(1), 5-14.

Results and Discussion No main effects or interactions for sexual orientation or race Significant sex differences in muscle group focus and exercise type Evolutionary motivation – desire to look attractive Through exercise, enhance attractiveness and probability of higher quality mate Jonason, P. K. (2007). An evolutionary psychology perspective on sex differences in exercise behaviors and motivations. The Journal of Social Psychology, 147(1), 5-14.

Male Upper Body Size and Definition Relevant to selection by all female primates Aid in intrasexual competition Highly correlated with dominance and strength Jonason, P. K. (2007). An evolutionary psychology perspective on sex differences in exercise behaviors and motivations. The Journal of Social Psychology, 147(1), 5-14.

Female Lower Body and Weight Loss Proximate vs. Ultimate causes and motivations Motivated to attract mates Intrasexual competition Loss of weight enhances signal of reproductive health and capacity Jonason, P. K. (2007). An evolutionary psychology perspective on sex differences in exercise behaviors and motivations. The Journal of Social Psychology, 147(1), 5-14.

Critical Review Items: A – Three Interesting Points The section of the article relating to intrasex competition was of particular interest. According to evolutionary theory regarding exercise behaviors, the ultimate motivation would be to look appealing in order to find a mate. For women this means looking smaller (while not in the extreme) and more feminine as determined by a healthy weight and waist to hip ratio (WHR). Men on the other hand should appear larger, stronger and more dominant. In order to compete with those within ones sex to obtain a mate and reproduce, one must work to maintain or achieve these characteristics connected with maleness and femaleness. In today’s society we are overwhelmed with images of thin women and it is easy to blame media for our culture’s obsession with weight, but as Jonason points out that would only be dealing with the proximate and not the ultimate cause. Femininity attracts men, leading to reproduction which is our innate drive. Therefore, to blame media exposure would be too simplistic when in reality it is our evolutionary motivation to attract mates. When Jonason claimed that women prefer men whom are taller, darker and bigger, we found it very interesting. We started to see how adaptations like these are having positive and negative effects. On the positive side, it has become a motivational factor for men to stay in shape. Unfortunately, it has also caused serious health risks such as men using steroids and other enhancements which can be very dangerous. Jonason, P. K. (2007). An evolutionary psychology perspective on sex differences in exercise behaviors and motivations. The Journal of Social Psychology, 147(1), 5-14.

Critical Review Items: B – Three Weak or Unclear Points Jonason reported that a small percentage of the participants identified as homosexual after reporting the demographic information of participants. Later, the researcher explained the importance of the racial diversity of the participant group, but never further explained the implications for participants whom were homosexual. Perhaps Jonason could have further explained the relevance or implications of this study for people who identify as homosexual. It may be that motives do not change in this specific population, but further explanation or study would be interesting. It would have been interesting to get more information on why some women take weight loss to the extreme when it can result in the inability to bear children. If our behaviors and actions can be related back to the evolutionary need to reproduce, why would some women risk it or in other words, why has the desire for thinness overtaken the natural instinct to procreate? Jonason made the statement that based on his sample, the study is more “generalizable to a general college population and perhaps to the population at large” (Jonason, 2007). In our opinion, this statement is weak. Although he sampled a large population of college students, they were all from one general area and it is important to note they were college students. His sample is not appropriate for making a generalization about an entire population; it is even a little far- fetched to generalize it to all college students. Jonason, P. K. (2007). An evolutionary psychology perspective on sex differences in exercise behaviors and motivations. The Journal of Social Psychology, 147(1), 5-14.

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