There is virtually no psychological difference between the sexes, and suggestions in books such as Men are from Mars, Women from Venus are nonsense, experts say.
Men and women have traditionally been said to possess distinct personality traits that make them so dissimilar they may as well come from different planets.
But psychologists claim they have debunked the idea that the sexes think in completely different ways in a study that found qualities such as empathy are not the sole preserve of one gender.
Although there are small average differences between men and women for some qualities, such as aggression, there is so much overlap that no trait can be designated as either male or female, they found.
The findings explain why gay and lesbian couples have the same sort of arguments as heterosexuals, demonstrating that it is not gender but individual characteristics that cause friction in relationships, the psychologists said.
Writing in the Journal of Personality and Social Psychology, they claimed: "Contrary to the assertions of pop psychology titles like Men Are From Mars, Women Are From Venus, it is untrue that men and women think about their relationships in qualitatively different ways." The psychologists reanalyzed data from 13 earlier studies which claimed to show there were significant psychological differences between the sexes.
The results were generally based on questionnaire responses.
The research covered 13,300 people and contained information on 122 characteristics including intimacy and sexuality, as well as the so-called "big five" traits which are said to define our personality: Extroversion, openness, agreeableness, emotional stability and
The psychologists found that while certain stereotypical activities, such as boxing or using cosmetics, were more common among one gender, no such divide existed for most personality traits. Many of the men were found to be empathetic, a quality traditionally seen as "female," while women were often good at maths, a so-called "male" skill.
There were overall differences between the sexes on average, but in virtually all categories there was a great deal of variability within each sex and overlap, meaning the characteristics cannot be said to "describe" either sex accurately, the psychologists found.
People who scored very stereotypically in one category did not necessarily do so in others, meaning a man with a high score for aggression may rank no higher than women in other "male" characteristics such as maths ability, the American researchers added. Professor Harry Reis of Rochester University, a co-author of the study, said: "People think about the sexes as distinct categories. 'Boy or girl?' is the first question parents are asked about their newborn, and sex persists through life as the most pervasive characteristic used to distinguish categories among humans.
"What we found is that overwhelmingly, men and women were not categorically different people.
"There may be characteristics that women have more of, there may be characteristics that men have more of, but it's not a case that men and women are fundamentally and dramatically different on these psychological characteristics."