Women are commonly assumed to be more emotionally turbulent than men: moodier, more volatile, and more likely to experience rapid changes in affect across the course of the menstrual cycle. Aside from being the basis of many a sexist joke, this assumption has had an impact on research, with cisgender women excluded from research due to apparent fluctuations in mood.
Building on research exploring fluctuations in rodents, a team from the University of Michigan has looked more closely at such variability in humans. Their study in Scientific Reports finds no difference in emotional variance between cisgender men and women, or between women who do and do not use oral contraception.
Participants were cisgender men and women aged between 18 and 38. Some women were not on any form of oral contraception, while others were taking the pill. Every evening for the entirety of the 75-day study, participants rated how much they had experienced ten positive and ten negative emotions in the last day.
The team used this data to look at three key areas: how volatile each participant’s mood was, based on how much it varied from their average mood; their emotional inertia, or how much their mood on one day predicted mood the next day; and how cyclical their moods were, based on how frequently they experienced specific changes in mood.
The team found very little statistical evidence for differences between men and women on any of these measures (in fact, men showed slightly more variability in mood than women). Similarly, there was little evidence that women on oral contraception differed from women not using contraception.
This has significant consequences in research settings. As the team notes, cisgender women are being excluded from research because of a perception that their moods are unstable — but if this isn’t the case, as these results suggest, this could create opportunities for researchers looking at a great number of different topics.
More work needs to be done on the variability of moods for women on the pill. Anecdotally, the pill can cause serious mood swings, while some research has been done on the link between the pill, mental health, and mood.
The team is not suggesting, however, that oral contraceptives (or endogenous hormones) play absolutely no role in mood. Indeed, the study compares differences in variation in men and women rather than looking at the specific impact of hormones on mood, and the team notes that a combination of factors including diet, sleep, exercise, social interactions and other contexts can combine to influence variability in and volatility of mood. While our hormones undoubtedly play a part in how we feel, they are simply part of a wider tapestry of factors that may or may not have anything to do with our gender.
– Little evidence for sex or ovarian hormone influences on affective variability
Emily Reynolds is a staff writer at BPS Research Digest
