"Opposites Attract?"

Not According to Gene Researchers: Study Shows Genetics Influences Choices in Friends, Mates" -- Lee Dye of ABC News explains J.P. Rushton's latest study;

- The reason our friends seem a bit kooky, and our mates may seem strange compared to ourselves, is that opposites attract. Right?

Nope. A large body of research suggests that we pick our friends, as well as our mates, because underneath it all they are very much like us.

So if our friends are kooky, and our mates a bit strange, chances are we are too.

And the latest study in this ongoing research takes it a little further. We can blame it at least partly on our genes. People tend to like others who have the same inheritable traits, so we often choose friends and mates who are genetically similar to ourselves.

"People prefer their own kind," says J. Philippe Rushton, a psychologist at the University of Western Ontario. "Extroverts favor extroverts; traditionalists, traditionalists."

That may not jibe with your own experience, but Rushton notes that genes are not the only players. We're not a bunch of robots that are being led around by genes that even pick our friends. Other factors, according to the researchers, play a significant role.

Rushton says our friends and our mates may also be a product of the "unique environmental effects such as being in the right place at the right time." You can't link up with an ideal mate if the two of you never meet.

Our genes, Rushton says, probably account for about a third of the reason why we pick someone else as a friend or a mate.

"But that's still pretty strong," he says. "Let's say it's a strong whisper from the genes."

Rushton, who has been researching this subject for 20 years, says clear patterns emerged from a study of hundreds of identical and fraternal twins, as well as their spouses and friends. It's no surprise that identical twins, who share 100 percent of the same genes, picked friends and mates who were very similar to those picked by their twins.

But here's the twist. Fraternal twins, who share only 50 percent of their genes, picked friends and spouses who are so much like themselves they could be their brothers and sisters. And, Rushton says, so do the rest of us. "It's almost as similar as siblings," he says. "Not quite, but almost." [More]

When thinking about how much genes drive behavior, it's often useful to think about how surprisingly different siblings can be. Don't leading men Jeff Bridges and Dennis Quaid seem more like they would be brothers to each other than to their own real brothers, character actors Beau Bridges and Randy Quaid respectively?

So, it's not really that amazing that best friends and spouses are as much alike as siblings, since siblings aren't anywhere near as similar as identical twins are.

Of course, spouses need to be different on some dimensions, otherwise you won't get much sexual attraction. Very few people are narcissists. (That's why homosexual relationships tend to run out of steam faster than heterosexual relationships.)

One model might be to distinguish between sexual/romantic attraction, which is driven more by differences; and social attraction, which is driven by similarities. The top advice columnists in the US, the identical twin sisters Ann Landers and Dear Abby, recommended looking for somebody to marry who was from a similar social background as you, but had a different personality.

Somewhat similarly, friends typically need a few differences for a particularly good relationship so that they are complementary, with some synergy to their pairing.

One of the most interesting things I've heard from twin expert Nancy Segal is that identical twins seldom fall in love with the same person. Typically, they approve of their twin's choice, but don't share the passion.

On the plus side of Ruston's genetic similarity theory, I've noticed quite a few times that mentor-protégé pairs in business often look highly similar. For example, Robert Redford helped launch Brad Pitt's career in A River Runs Through It, in which director Redford had Pitt made up to look just like him as a young man. Here's my review of their second movie together, Spy Game, in which I discuss Rushton's theory.

My published articles are archived at iSteve.com -- Steve Sailer