BY NOW IT’S AN OLD SAW: Men are from Mars, women from Venus. Yet according to Marianne J. Legato, a physician and professor of internal medicine, science is only beginning to uncover just how different the sexes truly are. Here, the founder of the field of gender-specific medicine explains how this research has effected changes both profound (saving women’s lives) and basic (showing men and women how to communicate better).

Q: How did you come to create the Foundation for Gender-Specific Medicine?
A: I had been studying the molecular biology of the heart at Columbia University for 20 years when in 1990 a journalist asked me to collaborate on a book about women and coronary artery disease. I replied, “What are you talking about? There’s no difference in how men and women experience the disease.” She responded, “My mother died of it. Many of her complaints were written off as silly or hysterical.” We wrote The Female Heart, the first book on the topic.

Q: What are the differences, then?
A: Men’s and women’s heart muscles are composed of different proteins, and their hearts’ electrical systems are not wired in the same way—which can make them function very differently. For example, 20% of women having a heart attack don’t feel chest pain; instead, they have symptoms that an inexperienced emergency room physician might mistake for a gall bladder attack. Women have died in the hospital parking lot because they were sent home.

Q: As you wrote The Female Heart, your thoughts turned to how other organs might differ, such as the brain. Could you explain the title of your new book, Why Men Never Remember and Women Never Forget?
A: In prehistoric times women had to remember where to find the best food and where danger lay; as a result they are still hardwired to retain exquisitely detailed memories. Men, on the other hand, had to hunt dangerous animals, so it didn’t behoove them to have detailed memories of painful experiences. But it did behoove them to take risks without undue anxiety or fear. It also helped that their pain was dulled by testosterone.

Q: How is it that a man and a woman can experience a quarrel completely differently?
A: During an argument, both men and women secrete the stress hormone cortisol. Men secrete a burst of the hormone that lasts just an hour, after which they feel upbeat and energized. In women, estrogen prolongs that secretion for almost 24 hours, clouding their ability to think clearly. So when a woman, who is still anxious the next morning, says, “I’d like to return to this issue,” her husband might well answer, “What issue?”

Q: In light of these differences, what should women do?
A: Keep a conversation factual and brief. One of my patients complained of her husband’s ineptitude when she sent him to the store for peanut butter and expected him to get jelly and bread too. Men do exactly as they are told.

Q: And what can men learn?
A: It’s important not to shut a woman down when she wants to talk. Many women verbalize a problem to arrive at a solution.

Q: Do these brain differences have an impact on depression?
A: Researchers say that women are twice as likely to suffer from depression as men are—probably because they assume that both genders have the same symptoms. In fact, I think that depression is tremendously underdiagnosed in men because their symptoms are different: Men tend to become quiet and solitary, drink more and become irritable, even violent.

Q: There are times in life when hormones cause men and women to become a bit more alike.
A: In the first throes of infatuation, men and women are most alike; they have heightened levels of norepinephrine and epinephrine, which make them sleepless and obsessive. When a woman is about to give birth, her husband’s testosterone levels fall, making him less likely to roam and more likely to bond with his wife and new baby. And as testosterone levels dwindle in older men, they become dependent on their wives’ companionship.

Q: Could innate differences between men and women be a reason fewer women succeed in science?
A: No. Men and women can accomplish the same things; they just use different brain systems—and thus different techniques—to do them. When NASA put people into a virtual maze, women used landmarks, whereas men used what are called Euclidian principles—akin to using a compass—to find their way out.

Q: What changes do you hope to achieve with your work?
A: Assuming that women and men are identical without testing that hypothesis is against everything we have been trained to do as scientists. In testing that hypothesis with coronary artery disease, we have saved hundreds of thousands of women. With research into a number of diseases and organ systems, we will be able to save more lives and develop more effective medications. By applying this science, we will improve the quality and length of life for both sexes.