Genetics, Social Pressure, and Sexuality

Throughout history, humans have constantly questioned their own existence and pushed to define and give names to all aspects of humanity. As time has progressed, many means of identification have come to be named and defined, which has forced us to push deeper into our own understanding of ourselves. This results in a seemingly never-ending cycle of creating questions and trying to answer them. Recently, a large topic of discussion has been sexual orientation.

While scientists have been studying variation in human sexual orientation for a long time (Apostolou 1 mentions a study dating back to 1959), it has been known and studied for even longer that other species in the animal kingdom have same-sex relationships and attractions.  Bailey and Zuk provide an extensive summary on the studies of same-sex sexual behavior in non-human animals, which is recapitulated by Jha. But today, the focus of these studies have turned away from non-human animals and is, instead, trying to explain why humans have sexual orientations that span the spectrum from homosexual to heterosexual.

As we’ve begun to acknowledge sexual orientation in humans beyond heterosexuality, there has been a great deal of questions posed as to how different attractions exist. The biggest question that arises is, ‘why hasn’t natural selection got rid of whatever it is that creates same-sex attraction?’ There has also been a great deal of question surrounding how same-sex attraction affects overall fitness or if there is a link at all between fitness and same-sex attraction. Natalie Walchover began to explain how same-sex attraction exists in males and females in 2012. This was later expanded on in 2016 by Apostolou to include many different evolutionary theories as well as a recapitulation of hypotheses and previously conducted studies.

I found it very interesting that sexual fluidity exists in both males and females in different non-human animals; whereas in humans, the general consensus seems to be that females are fluid and males are typically rigid (meaning they are typically either attracted to one sex or the other). There are also stronger proof of genetics playing a major role in male same-sex attraction opposed to females. If all of this is to be considered true, then how are we now so fluid in terms of sexuality in regards to both males and females?

Storrs reports on an increase in bisexuality in both females and males (even though females do have a higher percentage of reported bisexuality than in men – as is to be expected considering the studies and information mentioned previously). [It also can’t go unmentioned the numerous people who identify as asexual, pansexual, demisexual, etc.] I believe that this increase is dependent on two factors: genetics and social pressure.

In the setting of today’s technology it is easy to say that same-sex attraction (or even no attraction in the case of asexually identifying people) has no — negative — effect on fitness. Thanks to modern medicine (though this was also the case before modern medicine), people who have same-sex attraction can reproduce. This means that their chances of leaving off-spring in the next generation could be considered equal to that of people attracted to the opposite sex (heterosexual). If same-sex attraction is genetic than it is possible for that gene to passed down to the next generation. The studies mentioned previously state that increased levels of hormones in the womb seem to be a large contributing factor to homosexuality/ same-sex attraction – these increased levels could be sustained and passed down to the next generation. Because people who experience same-sex attraction are not more or less fit than anyone else, it could possibly mean that genetics play a large factor (in that fit people with same-sex attraction are passing this gene to the next generation).

Social Pressure:
Another possible attributing factor to consider are social pressures; to be unique, to be different, to be part of the ‘hype’. While there are not many notable studies/ research done on this topic, it has definitely been part of the discussion in recent years. Societal acceptance of homosexuality, on many platforms, has been a hot-topic in many countries around the world. It is the cause of a huge divide in the United States of America (particularly in regards to the right to marry). There have been claims made on one side of the divide that people pretend to be/ ‘make up’ being attracted to the same-sex, or that they do it to rebel or get attention. Some people who do not experience same-sex attraction cannot seem to comprehend how anyone possibly could and make these claims (perhaps in an attempt to justify to themselves what they can’t understand). While I do not believe that people are ‘faking’ same-sex attraction — this is to say that I do believe attraction is rooted in genetics — I do believe that the attention surrounding the subject has opened up the door for people who are homosexual, et al, to be more honest about their attractions. I think that the increase in numbers of people identifying outside of heterosexuality is because more people feel comfortable expressing what they are feeling. Looking back on Bailey and Zuk, it is evident that many non-human animals are more fluid in their sexuality (meaning they will mate with the opposite sex for reproduction, but also mate with the same sex – and it is split on the gender line). Being a part of the animal kingdom, it would not come as a surprise to me that we are equally as fluid — but have only just began discussing, categorising, and studying it. The social pressure to ‘be yourself’ and ‘dare to be different’ may actually be providing a key for researchers of human homosexuality, as more people are now being upfront and honest about their attractions and are presenting that information to the world.

It will be interesting to see what researchers will be publishing in the years to come. I think that we are finally in a position to begin to better understand the relationship between evolution and sexuality, genetics and sexuality, and society and sexuality.

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What do young adults living in the United States think and know about sexuality, its cause and ability to sustain throughout the years?
Check back for a short documentary film addressing this question and thoughts on the genetic/social impact on the increase of non-heterosexual identification in recent years.

1. Apostolou, Menelaos. “The Evolution of Same-Sex Attractions: Parental and Intimate Partners’ Reactions to Deviations from Exclusive Heterosexual Orientation.” Personality & Individual Differences, vol. 101, 15 Oct. 2016, pp. 380-389.
Photograph by Miranda Dean. Copyright: Miranda Dean Images

6 thoughts on “Genetics, Social Pressure, and Sexuality

    1. Thank you! I feel like the social aspects tend to get pushed aside or ignored in a lot of studies, but I consider it to be very important. So, I wanted to try to tie the two aspects in together in this post. I’m glad you found it interesting!


  1. This article really got me thinking about the impact genes have on expression of sexual orientation. I also had never really given any thought to the effect of alternate sexuality preferences had on evolutionary fitness as these individuals are often still biologically able to reproduce, so this post was very interesting to me. I also thought the way you broke down the contributing variables (genes and social pressure) was very helpful in individually identifying the contributions from both variables on fitness and evolution. Great work.


  2. Great stuff here! Talking about ‘sexual fluidity’ brings up the concept of nature/nurture. How might we think about sexual orientation in this context? What does it mean to say that attraction is rooted in genetics? Can we not be flexible enough to expand our sexual attraction/behavior (environment)? What are the specific traits that may influence fitness? Is human male sexuality really that rigid? All of these questions are for anyone reading this!


  3. It is amazing to think about the many different factors that come into play when viewing sexual orientation. Social pressures and the stigmas many people attach to individuals are very daunting and difficult to overcome. It is a very interesting article and makes one wonder how many studies will be done in the different fields to better understand and enlighten the public so they can be more informed and less judgmental. Great article!


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