Sex Differences in Response to and Recovery from Stress
One of my favorite Radiolab episodes was from Season 2, episode 4, and is called “Where Am I?” [All of the best episodes are from their first few seasons, in my opinion. In more recent years – since 2008 or so – the episodes have been less science-y and more storytelling with only a very slim scientific connection. Maybe it’s more enjoyable for the lay public, but it’s pretty sad to me because, although I love storytelling podcasts, I miss those big questions that Radiolab used to tackle. Now it’s just another This American Life, but not as good as This American Life.]
Between 6:00 – 9:00 min into the episode is a segment about how we feel ourselves on the inside (called interoception) and how that helps us define our emotions. One theory, in fact, is that all emotions are really interpretations of our visceral senses, which are the inner senses of our body, signaled to our brain via the cranial nerves, particularly the vagus nerve (aka cranial nerve ten/CN X), as first postulated by William James and called the James-Lange Theory of emotions. After that, around 9:00 – 14:00 into the episode, is a mini dramatic sequence where Robert Krulwich argues with his wife on the phone, then they appear to resolve it, but then just moments later his wife continues the argument. After this there is a discussion with Stanford researcher, Robert Sapolsky, about the gender (although it’s more appropriate to say ‘sex’ because ‘gender’ is a social construct and does not depend on your sex hormones) differences in recover from stress (or, really, the autonomic nervous system – ANS). His research has shown that for both men and women, the ANS is activated at similar speeds or kinetics. However, the deactivation or resolution of the ANS is much slower in women than in men, which comes across as men “letting go” more quickly and women seeming to hold on to the same emotions for longer.
The autonomic nervous system, or ANS, is called such because we have no voluntary control over it, or so they say. The truth is that we can learn a certain amount of control over it, just like how we learn to hold our bladders until we can get to a toilet to relieve ourselves. For simplicity’s sake, however, we say that we have no voluntary control over it because, to a large extent, we do not. As you may recall, there are two branches of the ANS: the sympathetic nervous system (SNS) and the parasympathetic nervous system (PNS). The SNS is responsible for the “fight-or-flight” response to threats, while the PNS is responsible for the recovery and relaxation, energy reserving phase after the “fight-or-flight” phase. In general, we aim to spend most of our time in between these two states of being, erring on the side of the more calming, PNS state. Most, if not all, therapies for anything having to do with the body aim to help the subject get into and stay in the PNS state, including neurofeedback, but also acupuncture, massage, psychotherapy, hypnosis (an even deeper state), etc. When you’re in the SNS, you’re unable to do anything but survive. The primary issue is when you get stuck in a SNS-dominant state and cannot move out of it into a more PNS-dominant state. What Dr. Sapolsky’s research indicates is that women’s bodies take longer to exit the SNS-dominant state due to differences in the breakdown of the factors (hormones, etc.) involved in the activated state, so they feel like they’re still upset even after the appearance of resolution. This is why men and women tend to have different timelines in their arguments, while men “get over it” more quickly than women.
There are more implications of this research than just differences in the way men and women resolve their arguments. Many of the implications are physical (such as heart rate, blood pressure, and metabolism) – stress is more physically damaging to women than to men, and these differences vary within the women’s menstrual cycle and depend on the level of circulating estrogen (which causes this increased reactivity along the hypothalamus-pituitary axis [HPA]). Of course, this suggests that women lose out when compared to men in response to stress; however, there is another aspect to the sex differences in stress responses that demonstrates why women do not exit the stress response as quickly as men: it’s because women tend to respond to stress in a nurturing, relationship-building manner – what is called “tend-and-befriend” (as opposed to “fight-or-flight”). The fight-or-flight response in men makes sense as a very high adrenaline response, which would deplete the man’s energetic resources fairly quickly, thus necessitating a quick resolution of the response. However, the tend-and-befriend response is less energetically taxing to the woman’s body and may even require a longer period to execute properly (it takes longer to build relationships than to destroy them), thus extending the response time until its resolution.
Whenever one talks about sex differences where the words “gender” and “sex” are intermixed (due to a fundamental misunderstanding of their different meanings) there is a lot of miscommunication that can occur. Again, to clarify, we’re talking about sex hormones driving the difference in the time it takes to break-down or metabolize the endocrine factors (neurotransmitters, hormones, etc.) that are involved in the sympathetic nervous system.
Finally, it occurred to me recently after another failed attempt at dating that the initial feelings of romantic or sexual attraction feels a lot like the fight-or-flight response (including the “freeze” variation), which suggests that it is driven by the sympathetic nervous system. It’s definitely automatic, since it’s not voluntary! Then I looked up on Pubmed (database of primary bio-medical publications) and found that, indeed, the sympathetic nervous system is activated during romantic and sexual attraction – in women! Apparently, erections in men are driven by the parasympathetic nervous system (PNS), while the orgasm is driven by the SNS. In any case, following the logic of this blog, we finally have a physiological explanation for why women tend to have a harder time getting over break-ups than men do! (And I have an especially hard time, but that’s another story altogether!)
So hetero women out there: it’s perfectly natural that you are holding on to the relationship for longer than he is – it’s your biology. However, don’t expect him to understand, that’s his biology. Womp womp. It probably also explains why lesbians tend to stay friends with their exes (of course, this is mostly not the case for me, but I do see it a lot with my friends).
Lastly, neurofeedback does help reduce the half-life of the ANS for those of us who feel like we have extra-long half-lives. I have personally witnessed this in myself after doing many sessions of neurofeedback; I can “let go” much more easily than I ever had been able to in the past. No combination of medications or talk therapy has ever gotten me even close to feeling more able to “let go”, but I did learn a lot of better coping techniques so I wouldn’t behave regrettably when it took me longer to “let go”. Now I don’t even need to use those coping techniques nearly as much since I don’t even feel it as badly – I feel like I can naturally move on sooner, and that honestly feels like a miracle! Come in and find your own miracle if you’ve experienced similar difficulties!