A new study published in the Journal of Personality and Social Psychology has revealed the seismic news that men and women are categorically the same. “The common belief that men are from Mars and women are from Venus is really wrong, we are all from planet Earth”, said Harry Reis, professor of psychology at the University of Rochester and co-author of the study.

Reis and lead author Bobbi Carothers from Washington University in St Louis, looked at previous studies, analysing 122 different characteristics such as fear of success, intimacy and empathy in 13,301 individuals. They found that on the whole, men and women did not fall into different groups. “Although gender differences on average are not under dispute, the idea of consistently and inflexibly gender-typed individuals is”, said the study.

“It is not at all unusual for men to be empathic and women to be good at math — characteristics that some research has associated with the other sex”, explained Carothers. "Sex is not nearly as confining a category as stereotypes and even some academic studies would have us believe."

Dr Kellie Burns, a gender expert from the University of Sydney welcomed the new research as an important step in challenging ideas around gender. “This research confirms something we already knew”, she says. Gender difference "is an outmoded and limited way of seeing relationships and I think it is an easy way to operate within relationships because it justifies behaviour and patterns in some relationships. I think that science is used to justify gender difference as natural but there is resounding evidence that our culture, society, norms, expectations, customs and ideologies play the most significant role in shaping the gender order.”

It has been more than 20 years since John Gray’s bestselling book Men Are From Mars, Women Are From Venus helped define relationships for a generation of women based on differences between the sexes. Since then it has remained a popular way of explaining common problems couples face trying to get along.

During the mid 1990s, it seemed almost every woman I knew was reading Men Are From Mars. I remember my boyfriend’s mother lending me her well-thumbed copy. Together with my girlfriends we used it as a manual to try and understand some of the more baffling behaviour of our partners. Why would our boyfriends’ eyes glaze over when we wanted to talk? Why did they prefer to go to the pub and watch the rugby on Saturday afternoons than see us? Why did they run away to their “man cave” at the slightest hint of the word commitment? There seemed to be little point trying to understand the opposite sex if what Gray was teaching us was correct — they were as unfathomable as alien beings.

Relationships Australia counsellor Denise Reichenbach says she found Men Are From Mars was useful for explaining in an easy to access way why some couples struggle with one of the biggest issues in a relationship — communication. But she adds that she knew the book wasn’t the whole truth. “I guess working in counselling and with couples, I always knew that there were a lot of different factors that come into play and although we might say men might react differently in some situations to women, it doesn’t mean it will be like that in every case. You can’t blame everything on gender because human relationships are much more complex than gender.”

Dr Lissa Johnson, a clinical psychologist based in Sydney with more than 15 years counselling experience, says that many individuals still buy into the notion that men are from Mars and women are from Venus to the detriment of their relationships. “I do find that men and women often fall into the trap of stereotyping each other, which can disconnect them from their common humanity and cause problems in relationships. I find that it is not unusual for women to underestimate the depth of mens’ emotions and the degree of their vulnerability, particularly in relationships, which can cause a lot of misunderstanding and unnecessary disconnection. It is also not unusual to have conversations in therapy about the universality of basic human psychological needs, and men and women can be surprised to discover their shared experience in this regard.”

So whether your partner forgets an anniversary or prefers to withdraw rather than talk, pinning any annoying traits on their gender might be misguided - it could just be who they are. And who knows, even the script for the big screen adaptation of Men Are From Mars, Women Are From Venus, reported to be shooting now with Reese Witherspoon, might require some heavy rewriting.