Are There Differences in Male and Female Brains? Yes

How to Build a Latticework of Mental Models

This article is an excerpt from the Shortform book guide to "Brain Rules" by John Medina. Shortform has the world's best summaries and analyses of books you should be reading.

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Do sex and gender affect the way we think? Is there evidence of differences in male and female brain structures?

While most of the cognitive differences between male and female brains are shaped by social expectations, there are some differences that molecular biologist Dr. John Medina suspects have a profound impact on behavior. Medina posits that the male and female brains react differently to a number of situations.

Here are the physical and psychological differences in male and female brains.

Physical Differences in Male and Female Brains

Dr. Medina notes that there are observable differences in male and female brains. For example, various regions of male and female brains have different sizes. The frontal and prefrontal cortex, which deal with decision-making, is larger in women. The limbic system, on the other hand, is larger in men. This system contains the amygdala, which controls the generation and memory of emotions.

One difference in male and female brains is that they have different chemicals. Serotonin, which regulates emotions, is much higher in men than women. While male and female brains have differences, these differences don’t necessarily affect how men and women behave. This is because, according to Medina, neuroscientists have not found a definitive link between brain structure and behavior.

Brain Structure Doesn’t Strongly Influence Behavior

Although Medina suggests otherwise, recent research indicates that gendered differences in brain structure are unlikely to shape how we behave. Researchers have noted differences in behavior among men and women and differences in male and female brain structure—most notably that male brains are typically 10-15% larger than female brains. However, when they compared differences in brain structure with differences in behavior among study participants, they found that brain structure did not have a statistically significant impact on behavior.

Gendered Behavioral Differences

Medina describes numerous behavioral differences between men and women, which he believes affect social and professional relationships. Some research shows that women and girls are generally better at verbal communication than men and boys. Medina notes that this is likely because women tend to use both hemispheres of the brain when speaking and processing verbal information, whereas men tend to use just one.

Male and female children also form relationships differently, a pattern that extends into adulthood. Girls tend to bond by talking frequently, while boys bond through physical activities. And while girls prefer to form a consensus with another in social groups, boys prefer a social hierarchy with a distinct “leader”. When these styles of relationships persist into adulthood, they can cause social and professional difficulties. For example, a woman with a “masculine” leadership style may be seen as “bossy,” harming her ability to advance in the workplace. On the other hand, a man who does not try to compete with his colleagues may be seen as weak or unmotivated.

Medina notes that gendered communication and relationship styles are a general pattern, and that individual men and women often don’t adhere to them. He also notes that boys and girls are treated differently from one another from an early age. This suggests, then, that social differences between boys and girls at least partially result from cultural gender norms.

(Shortform note: Recent research from cognitive neuroscientist Gina Rippon bears this out. Rippon believes that there aren’t meaningfully differences between male and female brains, but that the practice of treating boys and girls differently can shape their behavior—and since their brains are developing, their neural pathways.)

Gendered Cognitive Differences

Medina also notes several cognitive differences between male and female brains, which he argues affect both thought processes and cognitive health.

One cognitive difference is that men and women tend to respond to stress differently. Research suggests that, when responding to stress, men focus on the general overview of a situation, while women focus on the details.

(Shortform note: Research also shows that men respond to stress with a “fight-or-flight” response, while women respond with a “tend-and-befriend” response. This means that, when faced with a stressful situation, men are likely to either confront or avoid it, while women are likely to look for comfort.)

Men and women also tend to be susceptible to different psychological health issues. Men may be more susceptible to intellectual disabilities, schizophrenia, antisocial behavior, alcoholism, and drug addiction. On the other hand, women may be more susceptible to depression, anxiety, and anorexia.

(Shortform note: Most researchers believe that a combination of biological and cultural factors explain why men and women are susceptible to different mental disorders. Men and women have different hormones, which impact our mental health. Yet aspects of culture that affect gender, like discrimination and gender roles, can also cause harm to mental health. Scientists note that much more research is needed to better understand how biology and culture can create different mental health outcomes for men and women.)

Are There Differences in Male and Female Brains? Yes