Why We Need To Talk More About Women's Sex Hormones & Birth Control

Conversations about women's sex hormones can be a political hot potato. And this is because, for a very long time, they were used as an excuse to treat women as overly emotional, less rational versions of men. The recent political climate is a reminder that these sentiments have not totally gone away. Sexist ideologues continue to push the idea that women shouldn't be able to do important jobs because their ever-changing hormones make them wholly unreliable. However, this position is nothing short of ludicrous. 

To start with, although women's hormones vary cyclically, they're not capricious. They're actually remarkably predictable. As a leading evolutionary psychologist specializing in women's health, if you tell me a woman's age and the first day of her last period, I can predict with a great deal of accuracy what her sex hormone profile will look like at that moment. For a premenopausal woman in the first half of her cycle, I would predict that estrogen would be relatively high and progesterone relatively low. If in the second half of her cycle, I would predict that the reverse would be true. And if she was postmenopausal, I would predict that levels of both of these hormones would be low regardless of the day I was testing. Women can see the effects of this rhythmicity themselves by keeping a journal of how they think and feel across their cycle. They'll notice, as I have, that there is a lot of consistency in terms of how they feel when one sex hormone is dominant and then how they feel when the other sex hormone is dominant. So, although women's hormones may change cyclically and across the life span, they are anything but fickle or capricious. 

Interestingly, the same cannot be said about men's primary sex hormone, testosterone. Testosterone actually is fickle, fluctuating considerably in response to a number of factors present in a man's environment. For example, research indicates that men's testosterone changes in response to age, the time of day, getting married, having children, the presence of attractive women, the loss of a man's favorite political candidate, the win/loss of his favorite sports team, and (I'm not making this up) the presence of guns. And this is far from being an exhaustive list. Men's testosterone level changes all the time. This means that if I were to try to make a comparably good guess about what was going on with a man's primary sex hormones at a given moment, I would need to know, at a minimum, his age, marital status, whether he has children, and the time of day that he provided his sample, as well as a description of all of his recent activities, including whether he'd seen any attractive women, watched sports, or encountered any weapons on his way to the lab for testing. 

Men and women both have hormones that change. And when they change, they change what we think, feel, and do. This is what hormones do, and it is a good thing. It makes us smarter, wiser, and better at doing all the things we need to do, when we need to do them. They allow all of the parts of our bodies to work together to reach every one of our evolutionary destinations (e.g., finding a mate, having children, caring for children, bonding with loved ones, coping with stress, and so on), and do so without missing a beat. The idea that women's hormones change and influence behavior, but the idea that men's do not has no scientific backing. Instead, it is a position of convenience adopted by those who are trying to keep women from competing for the resources and positions that have long been monopolized by men. 

Given that there is no truth to the idea that women's hormones render them unable to act rationally, it is time to remove the taboo that surrounds conversations about women's sex hormones and their involvement in the brain.

Failure to acknowledge the important role our sex hormones play in influencing how we think, feel, and behave is bad for everyone, but it's especially bad for women. It prevents us from thinking clearly about the birth control pill, which is a prescription medication that the majority of us will go on at some point in our lives. The birth control pill fundamentally changes women's sex hormone profile. And we are living in a time when women are routinely prescribed the pill, not only as a means of pregnancy prevention but also as the first line of defense in even the most minor of bodily annoyances, like skin breakouts and irregular periods. Many of us don't think twice about the wisdom of taking such a prescription because we have been taught from a very young age that our sex hormones are irrelevant when it comes to making us who we are. We are told that to believe anything else would put women back into the dark ages where we would not be allowed to vote or own land because our hormones made us irrational. 

But women need to be made aware of the important role their sex hormones play in making them who they are. Women's sex hormones influence attraction, sexual motivation, stress, hunger, eating patterns, emotion regulation, consumer behavior, status seeking, learning and cognition, and more. This means that the birth control pill is going to influence each of these systems, too. And a growing body of research in neuroscience and psychology has begun to uncover the surprising effects of the birth control pill on the brain. 

For example, researchers find that women on the birth control pill have stress hormone profiles that look more like those belonging to trauma victims than they do like those belonging to otherwise healthy young women. And this is important to know because these patterns can be linked to emotional problems and can have a negative impact on learning and memory. Additionally, because the pill can influence who women are attracted to, being on the pill may inadvertently influence who women choose as partners, with important implications for their relationships once they go off it. Sometimes these changes are for the better...but other times, they're for the worse.