"Masculinity is a spectrum and there are men who are more 'woman' than women in terms of 'female characteristics' such as empathy and compassion," he added. "Femininity is also a spectrum. On one end, some females have more testosterone and aggression than most men."
So why do people tend to segregate men and women into such separate stratospheres?
"It is the drama that we love," Karasu said. "These are the roles we are given to play."
But this role-assigning may actually be harmful, Reis said. For instance, if you attribute your mate's annoying behavior to immutable gender traits, he or she will have no reason to change.
"It would make me very happy [if people started seeing] these various qualities as human differences -- qualities that some people have more of and some people have less of -- and that a person's gender is a very small piece of that," Reis said.
And what about the idea that men are from Mars and women are from Venus?
"That idea should go into the trash can and, yes, you may quote me," Reis said.
The World Health Organization has more on gender.
SOURCES: Harry Reis, Ph.D., professor, psychology, University of Rochester Medical Center, New York; Byram Karasu, M.D., psychiatrist-in-chief, Montefiore Medical Center, New York City; February 2013 Journal of Personality and Social Psychology
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