Health & Science

Why some people are gay

Is homosexuality a “lifestyle choice” or an inborn characteristic? Recent scientific research has found strong indications that gay people are born that way, and a new Swedish study has provided the most definitive evidence yet. Detailed analysis of the brains of 50 straight people and 40 gays and lesbians has found that gay men have brains with architecture strikingly like that of straight women. Lesbians’ brains, on the other hand, are similar to those of straight men. In the study, which utilized both MRI and PET scans of the subjects’ brains, researchers found that straight women and gay men both have highly symmetrical brains, with equal-sized right and left hemispheres. In straight men, the right hemisphere is significantly larger than the left. The scans also found intriguing differences in the amygdala, the section of the brain that makes connections between stored information and emotional reactions. In straight women and gay men, the amygdala is rich in connections that allow for sophisticated interplay of thoughts and feelings. In straight men and some lesbians, the amygdala shows more “fight or flight” responses. “It’s a more action-related response than in women,” study author Ivanka Savic of the Karolinska Institute in Stockholm tells New Scientist. Researchers believe the brain differences originate in the womb during pregnancy; it appears that exposure to male hormones “masculinizes” the brain, and that when the levels of these hormones are unusually low during the gestation of a boy and high during that of a girl, the child’s sexual orientation becomes gay.

Chimps console each other

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Chimpanzees are human beings’ closest genetic cousins, and a new study has found that they share our ability to empathize with other members of their species—and that they express this sentiment in much the same way. When a chimp loses a fight or is the victim of aggression from an elder chimp, he’ll run off and sulk, scratching or grooming himself in a display of anxiety. That’s when another chimp will approach to show sympathy, offering a warm hug or a kiss. The expressions of sympathy clearly make the comforted chimp feel better, reducing his display of distress behaviors. The findings are significant, Frans de Waal of the Yerkes Primate Center at Emory University tells Discovery News, because empathy is a complex sentiment—one that monkeys can’t experience and even human children don’t learn until they’re older.

Sleeping with the enemy

Women in troubled marriages tend to sleep poorly and restlessly, while those in happy marriages usually get a good night’s rest, says a new study. University of Pittsburgh researchers analyzed the sleeping patterns of more than 2,000 women and compared them with their own evaluations of their marital happiness. They found that women who described their marriages as essentially happy had significantly less trouble falling asleep, slept more soundly, and were less likely to wake up too early or in the middle of the night. “All marriages aren’t created equal,” said psychologist and study author Wendy M. Troxel. “An unhealthy marriage is a potent source of stress. You could be sleeping with the object of your hostility.” If you’re not sleeping well, she says, it may be a signal that it’s time to get some marriage counseling.

I kissed a robot

In five years, people will be having sex with robots, and in 40, full-blown romantic relationships. So says robotics expert David Levy, the author of a new book called Love + Sex With Robots. The development of artificial intelligence and robots is now proceeding so rapidly, Levy says, that soon it will be possible to produce anatomically correct mechanical partners that are “sort of an upgrade of the sex dolls on sale now,” complete with sound effects. It’ll take quite a bit longer for robotic science to progress to the point at which artificial intelligence is capable of holding conversations with humans and forming a reasonable facsimile of a romantic relationship. But Levy says it’s inevitable. “You will find robots, conversation partners, that will talk to you and you will get as much pleasure from it as talking to another human.” It may seem grotesque to fall in love with a robot, but Levy says that for people with psychological problems or physical deformities, it could be a huge consolation. “There are millions of people in the world,” he says, “who have nobody.”

Why you have an appendix

The appendix has long been a medical mystery, says The New York Times. Nobody knows what function, if any, that little pouch in the large intestine serves. Most of today’s scientists consider it a vestigial organ—a remnant of our evolutionary past with no current importance, unless it happens to become inflamed or to burst; appendicitis is a life-threatening condition and usually requires surgery. But now, one doctor is putting forth a theory as to the real function of the human appendix. Dr. William Parker, a medical researcher at Duke University, has proposed that the appendix serves as a safe house for so-called good bacteria—those colonies of bacteria that help us to digest our food. If a serious intestinal infection were to occur, with a huge influx of bad bacteria completely wiping out the good, the appendix could serve as a hiding place for good bacteria, which would recolonize the intestines after the illness was over. Parker admits that he’s never actually seen this happen—in Western nations with good sanitation and medical care, severe, untreated gut infections are rare. “At this point, this is a deduction,” he says, but “it does make sense.”