Why Are Women More Fearful Than Men?

That women and men behave differently in some ways, on average, is not exactly newsworthy.  What may be more surprising is that some of these gender differences are found consistently worldwide, and are actually greater in countries with cultures and institutions that more heavily promote and enforce gender equality. One such difference is in the personality trait of neuroticism—the tendency to experience anxiety, depression, and negative emotions generally—on which women (on average) score higher than men. 

What accounts for this difference? Nicholas Kerry and Damian R. Murray of Tulane University found that differences between U.S. students in grip strength—the strength used in a bone-crushing handshake, which is strongly correlated with other forms of muscular strength—partly explained gender differences in self-reported anxiety, but did not explain gender differences in self-reported depression. Stronger people were less anxious, and men were, on average, considerably stronger than women. Therefore, much of the gender difference in anxiety was accounted for by the gender difference in strength. 

Is Fearfulness, Compared to Anxiety, Even More Affected by Physical Strength?

Anxiety is a tendency to worry about a wide range of dangers that might manifest in the future, whereas fear is the activation of the fight or flight response in reaction to an immediately present danger. My collaborators and I reasoned that, among all personality traits, fearfulness is the one most likely to be linked to physical strength. Certainly among ancestral humans, and to some extent even today, stronger people have been less vulnerable to physical harm, and more sought after as allies. In the presence of a hazard, such as a predator or a potentially violent person, it would be advantageous for stronger people to experience less fear than weaker people. In general, individual personality development may be responsive to a person's physical characteristics.

We collected data from more than 1400 undergraduates at four U.S. universities, including grip strength (measured with a hand-held dynamometer) and responses to a personality survey that included questions that measure emotionality, which resembles neuroticism in that it includes an anxiety component, but which differs from neuroticism in that it includes a fearfulness component that focuses on reactions to physical danger. Emotionality also includes two other components, sentimentality and emotional dependence. Cross-national research has shown that women score substantially higher than men in emotionality (including all four of its components), but we expected that the gender differences in physical strength would explain only the gender differences in anxiety and fearfulness. Sentimentality and emotional dependence have little to do with reactions to threats, so they should be weakly related, if at all, to physical strength.

Grip Strength Was Responsible for More Than Half the Gender Difference in Fearfulness

We did find that the gender difference in fearfulness, more than any of the other three components of emotionality, was partly explained by the gender difference in grip strength. For example, the average fearfulness score of the 8% of women who were stronger than the average man was lower than that of the 22.5% of the men who were the most fearful. In two of the five samples of university students, the gender difference in grip strength completely explained the gender difference in fearfulness—indeed, after statistically controlling for grip strength, the gender difference in fearfulness disappeared entirely.

As we expected, the gender difference in grip strength also explained a considerable proportion of the gender difference in anxiety, and it explained very little of the gender difference in sentimentality. Surprisingly, the gender difference in grip strength also explained a considerable proportion of the gender difference in emotional dependence.

Could Strength Training Reduce Fearfulness and Anxiety?

To answer that question would require tracking the same people over time or doing experiments comparing people who did and didn't get strength training. Research has also linked other personality traits, such as extraversion, to physical strength, but we don't know to what extent these can change in response to changes in strength during adulthood, as opposed to childhood experience. Given the worldwide prevalence of fear- and anxiety-related psychological disorders (such as generalized anxiety disorder and panic disorder), and their higher frequency in women than in men, this is an important question that might point the way toward an effective, relatively inexpensive intervention. It might turn out that spending a few hours a week pumping iron will improve your mental health as well as your physical health.

For Further Reading

Kerry, N., & Murray, D. R. (2021). Physical strength partly explains sex differences in trait anxiety in young Americans. Psychological Science, 32(5), 809–815. https://doi.org/10.1177/
0956797620971298

Manson, J. H., Chua, K. J., Rodriguez, N. N., Barlev, M., Durkee, P. K., & Lukaszewski, A. W. (2022). Sex differences in fearful personality traits are mediated by physical strength. Social Psychological and Personality Science. https://doi.org/10.1177/19485506221094086

Joseph H. Manson is a biological anthropologist at the University of California, Los Angeles, and a member of the Center for Behavior, Evolution, and Culture. He studies personality variation and small group processes from an evolutionary perspective