Essential Difference: The Male and Female Brain, The

Phi Kappa Phi Forum, Winter 2005 by Baron-Cohen, Simon

The field of sex differences in psychology is not new, though today it enjoys greater academic freedom than in past decades. The 196Os and 70s, while socially liberating, also made an open-minded debate about any possible role of biology contributing to psychological sex differences impossible. Those who explored the role of biology - even while acknowledging the importance of culture - found themselves accused of oppression and of defending an essentialism that perpetuated inequalities between the sexes. It was not a climate in which scientists could ask questions about mechanisms in nature. Today, the pendulum has settled sensibly in the middle of the nature-nurture debate, and scientists who care deeply about ending inequality and oppression can at the same time also talk freely about biological differences between the male and female brain and mind.

A new theory, known as the empathizing-systemizing (E-S) theory, claims that the female brain is predominantly hard-wired for empathy and that the male brain is predominantly hard-wired for understanding and building systems. "Empathizing" means the drive to identify another person's emotions and thoughts and to respond to those with an appropriate emotion. The empathizer intuitively figures out how people are feeling and thus how to treat them with care and sensitivity. "Systemizing" means the drive to analyze and explore a system, to extract underlying rules that govern the behavior of a system, and to construct systems. The systemizer intuitively figures out how things work, or what the underlying rules are that control a system. Systems can be as varied as a pond, a vehicle, a computer, a plant, a library catalogue, a musical instrument, a math equation, or even an army unit. They all operate on inputs and deliver outputs, using rules.

According to this new theory, a person (whether male or female) has a particular "brain type." There are three common brain types. For some individuals, empathizing is stronger than systemizing. This is called a brain of type E, but we can also call it the female brain, because more females than males show this profile. For other individuals, systemizing is stronger than empathizing. This is called a brain of type S, but we can also call it the male brain, because more males than females show this profile. Yet other individuals are equally strong in their systemizing and empathizing. This is called the "balanced brain," or a brain of type B (Figure 1 illustrates these profiles diagrammatically).

THE EMPATHIZING BRAIN

The evidence for a female advantage in empathizing comes from many different areas. For example, given a free choice of which toys to play with, more girls than boys will play with dolls, enacting social and emotional themes. When children are put together to play with a little movie player that has only one eyepiece, overall boys tend to get more of their fair share of looking down the eyepiece. They just shoulder the other boys out of the way. Or if you let children play with those big plastic cars that they can drive, what you see is that more little boys play the "ramming" game. They deliberately drive the vehicle into another child. The little girls ride around more carefully, avoiding the other children more often. This behavior suggests the girls are being more sensitive to others.

Baby girls as young as twelve-months old respond more empathically to the distress of other people, showing greater concern through more sad looks, sympathetic vocalizations, and comforting. This tendency echoes what you find in adulthood: More women report frequently sharing the emotional distress of their friends. Women also show more comforting than men do. When asked to judge when someone might have said something potentially hurtful - a faux pas - girls score higher from as young as seven-years old. Women are also better at decoding nonverbal communication, picking up subtle nuances from tone of voice or facial expression, or judging a person's character.

Sex differences also appear in aggression. Males tend to show far more direct aggression (pushing, hitting, punching). Females tend to show more indirect (relational, covert) aggression, which includes gossip, exclusion, and cutting remarks. It could be said that to punch someone in the face or to wound them physically requires an even lower level of empathy than a verbal snipe.

Two other ways to reveal a person's empathizing skill are to see how they (as a newcomer) join a group of strangers, and to see how they (as a host) react to a new person joining their group. These behaviors have been cleverly investigated in children by introducing a new boy or girl to a group of children already playing together. If the newcomer is female, she is more likely to stand and watch for a while, to check out what is going on, and then to try to fit in with the ongoing activity. Her trying to fit in usually leads to the newcomer being readily accepted into the group. If the newcomer is a boy, he is more likely to hijack the game by trying to change it, directing everyone's attention on to him. And even by the age of six, girls are better at being a host. They are more attentive to the newcomer, while boys often just ignore the newcomer's attempt to join in. Boys are more likely to carry on with what they are already doing, perhaps preoccupied by their own interests.