As you shop for a Valentine's Day gift, keep in mind that men and women often don't think alike or even like the same things.

As this ScienCentral News video reports, neuroscientists have looked inside our brains and found that men and women's brains are indeed different.

Are men and women fundamentally different?

The answer isn’t as straightforward as we’d think, at least when it comes to the brain. Jill Goldstein of Harvard Medical School’s psychiatry department says that although the male and female brain may be fundamentally similar, animal and human studies have shown that there are several differences in the size of particular brain structures. She points out that this has important implications for a variety of things: “These brain regions in which we find sex differences in brain structure have been found to be important in emotion, language, visual spatial skills, memory… or smell.”

Goldstein believes sex differences set in very early in the developing brain, even before we are born. The mechanisms that drive the secretion of the sex hormones, like estrogen, testosterone, androgen and others, determine the sex of an individual. In a paper published in the journal Cerebral Cortex, Goldstein reports that with the help of a scanning technique called magnetic resonance imaging (MRI), she and her team found that men and women differed in the size and volume of particular brain regions.

But that’s not all. Goldstein suggests that hormonal mechanisms during fetal development may help to explain some of the sex differences in psychiatric and neurological disorders that we see in childhood and adulthood. However, Goldstein adds that most of the studies looking at this have been conducted in animals, and research in humans is still in its infancy. She believes that, “understanding the mechanisms involved in explaining normal sex differences in the brain will help us understand sex differences in a number of psychiatric and neurological disorders.”

Does the difference affect our functions?

Although there may not be a direct relationship between size of different structures and their functions, Goldstein says, “Men have a slight advantage on certain kinds of functions, including target-directed motor skills—like throwing a ball—visual spatial skills, and navigating through a route. Women have a slight advantage for certain kinds of verbal skills, fine motor tasks, and accuracy in object location.”

This seems to make sense from an evolutionary point of view, where in a hunter and gatherer society, “the men who were (believed to be) the hunters, were required to have good visual spatial skills, so they could go out and provide food. Women were more likely to be gatherers and required fine motor skills.” But Goldstein reminds us that in the last 40 years sex roles have been changing, “So it will be interesting to see whether sex differences in brain structure will follow differences in sex roles over time.”

The study was funded by the National Institute of Mental Health and the National Institutes of Health's Office of Research on Women’s Health.