Q & A: Why do people have different sexualities and gender identities? From an evolutionary perspective?

March 8, 2023

Q&A blog post logo

Whoa! What an amazing question, and something that leads to even more questions. This question is loaded, so let’s break down a few things first. Sexuality, or more specifically Sexual Orientation, is defined as how someone identifies themselves in relation to the gender or genders they are attracted to. Gender Identity is how someone understands and experiences their own self in relation to their gender. A very important distinction to make between Gender and Biological Sex is that Gender may or may not be defined by an individual based on their genitalia or what is written on their birth certificate. Another thing to take into account is that gender is often socially defined – but more on that later.

Okay, so now that we have a very basic understanding of each of those, let’s take a look at how human beings experience sexual pleasure – no matter their sexual orientation. There are thousands upon thousands of pleasure-sensitive nerve endings around human genitalia, as well as throughout the body in other places. Researchers have theorized that we evolved to have these very densely around our genitals to encourage reproduction. In other words, if it’s pleasurable to have sex, then more human beings would be born. It is also notable that pleasure can be had in these more sensitive regions through masturbation, and isn’t determined by the gender of the one providing the pleasure. So that’s where the next piece of the evolutionary puzzle comes in: how do people have attraction to and desire for people of the same gender or multiple genders?

For insight on this, we look to the animal world – especially primates – to offer us clues as to where sexual behavior comes from. One area of primate studies is studying how their societies work. We find that in the primate world, same-sex sexuality is widespread (as well as many other animals). Analysis of observed behavior in primates suggests that it has many functions, including: appeasement, pacification, social tolerance, stress reduction, and barter. Heterosexual sexual behavior also shows a similar diversity in function across all primate cultures. Taking this into account, and operating under the premise that human beings have an equal or more complex societal structure, we can conclude that same-sex sexuality is simply a fact of existing as a primate. Humans do any number of things to bond, feel good, and create connections with each other. If that happens to be in the form of attraction to the same gender, then it is quite simply how someone is.

Although gender is (often confusingly) conflated with biological sex, or sex assigned at birth, it is an internal sense of the self in combination with society’s expectation of how someone should behave based on their biological sex or perceived biological sex. Okay, that’s a lot of words there that essentially means that the genitals someone is born with don’t dictate their sexual behavior, necessarily. There is a lot of media coverage and rhetoric around this very thing. Some folks believe that someone’s sex assigned at birth determines how they should or shouldn’t behave, while others believe that it doesn’t have to.

The way that we’ll end this very long response (thanks for sticking around this far) is by asking you, the reader, to think about some more-or-less rhetorical questions. How many people are there on the Earth? 8 Billion and rising… How many people have ever existed? Conservative estimates say at least 100 Billion. There have been – and will be – a plethora of experiences and identities out of  all of those cultures, histories, lifetimes, families, relationships, triumphs, mistakes, loves, and attractions. There have been – and will be – many types of identities and orientations that the human family will witness as a species.