Men are from Mars, and women are from Venus? Maybe not.

It's a pop psychology theory that has permeated modern culture, but a new study debunks the premise that men and women are irrevocably different in every way.

"A lot of people think about men and women as being different species somehow," said study senior author Harry Reis, a professor of psychology at the University of Rochester Medical Center in New York. "We wanted to hold that assumption up to rigorous scrutiny."

Reis and his coauthor analyzed 122 different physical and personality traits in more than 13,000 individuals. Their findings are reported in the February issue of the Journal of Personality and Social Psychology.

The conclusion?

Sure, men and women were physically different, the study found. And certain stereotypes held true with regard to hobbies and activities. But that's where the distinctions ended.

In terms of psychology, the thinking of men and women tended to overlap. In other words, men can be from Venus or Mars, and so can women, although it might be more accurate to say both genders are from Earth.

"We're accustomed to men having a penis and women having a vagina, then putting all kinds of attributes on them," said Dr. T. Byram Karasu, psychiatrist-in-chief at Montefiore Medical Center in New York City. "In reality, there's no such thing as men's and women's characteristics."