Do the pokie-pokie, stay out of the pokey?

Apologies for the title.

Lately, Slate has been writing about a very promising research design: When two variables tend to go together, and you want to see if one causes the other, check to see if they're linked in identical twins, too. Such twins share both DNA and a home environment.

In a new study, the connection between early sexual initiation and later delinquency was at issue. If sex in and of itself causes delinquency, when one twin has sex earlier, he should be more likely to get in trouble later on.

But that twin is actually less likely to become delinquent, according to the study. It seems there are genetic and/or environmental factors that contribute to both sex and delinquency, and once those factors are present, the kid's bound to act out in one way or another. If he chooses to act out via sex, sometimes it's apparently out of his system when it comes to delinquency.

Of course, the left is going crazy with this "sex-positive" finding, acting like we've uncovered a major benefit to teen sex. But the core message is still to create an environment that discourages all misbehavior -- presuming genetics don't completely determine one's actions, this will reduce the odds of both early sexual initiation and delinquency. This study doesn't change the fact that the two are linked in the population at large, meaning that eliminating the underlying factors will cut down on both problems.

I'd like to see similar studies looking at the impact of early sex on (say) emotional and psychological problems. All this one shows is that, if you have a child, early sexual encounters won't actually cause future delinquency, though they still predict it.