gender differences
Turns out men and women aren't so different.

That's according to new research by psychologists who examined personality traits, such as being good at math, being aggressive, being a good listener or empathetic, playing video games or talking with friends -- that many of us believe split men and women.

"Just because men and women look very different and sometimes have different interests and behaviors, we shouldn't assume that what goes on in our heads is just as different, at least with the psychological characteristics we looked at," said Bobbi Carothers, a data analyst at the Center for Public Health Systems Science at Washington University in St. Louis. At the risk of being cliche, I'd say the take-home message is "Don't judge a book by its cover."

Carothers and Harry Reis, professor of psychology at the University of Rochester, analyzed data from 13 sex-difference studies over the past few decades. The studies included data from more than 13,000 research volunteers, most of them college students. They also examined studies of adolescents and mature adults.

The pair analyzed 122 different qualities such as preferences over how to spend their free time: golfing or scrap booking? Bath or boxing? They also looked at the so-called Big Five psychological traits: extraversion (sociability and enthusiasm); agreeableness, conscientiousness, emotional stability, and intellect. Other analyses examined how men and women chose sexual partners and mates.

Instead of scores falling along neat lines between males and females, like height or physical strength differences -- psychological indicators fell on a spectrum for both genders.

There are average differences, but they are not large enough to classify men and women as consistently separate gender categories. Reis said that their statistical analysis shows that it's hard to tell men and women apart, even when it comes to sexuality.

"Many people act as if men and women are different species," Reis said. "The message to me is that these qualities don't belong to one sex, these are human differences and any given individual can have more or less than any of them."

The study flies in the face of pop-psychology best-sellers such as Men are From Mars, Women are From Venus that argue the genders are hard-wired to behave differently in psychology and emotions. The results of Carothers and Reis' analyses, "Men and Women Are From Earth," was published this month in the Journal of Personality and Social Psychology.

Carothers said her interest in gender differences started at a young age. She grew up with more sports equipment than dolls, and fished with her dad from when she could stand in a boat.

"I was aware that even though boys and girls were "supposed" to be different, those rules didn't necessarily have to apply to me, or really, anyone else if they didn't want them to," she said.