Super interesting -- and to me, reassuring -- cover story on the new science of siblings in Time last week. The fighting between our two boys can be insane some times; I used to say, during a particularly bad stretch a year ago, that if you left them in the same room for fifteen minutes, there was a 100% chance that one of them would try to do something to the other that would get you arrested if you did it to a stranger on the street. But apparently they're learning conflict resolution!

Laurie Kramer, professor of applied family studies at the University of Illinois at Urbana-Champaign, has found that, on average, sibs between 3 and 7 years old engage in some kind of conflict 3.5 times an hour. Kids in the 2-to-4 age group top out at 6.3--or more than one clash every 10 minutes, according to a Canadian study. "Getting along with a sister or brother," Kramer says dryly, "can be a frustrating experience." But as much as all the fighting can set parents' hair on end, there's a lot of learning going on too, specifically about how conflicts, once begun, can be settled. Shaw and his colleagues conducted a years-long study in which they visited the homes of 90 2-year-old children who had at least one sibling, observing the target kids' innate temperaments and their parents' discipline styles. The researchers returned when the children were 5 and observed them again, this time in a structured play session with one close-in-age sib. The pairs were shown three toys but given only one to play with. They were told they could move onto the next one only when both agreed it was time to switch and further agreed which toy they wanted next. That, as any parent knows, is a scenario trip-wired for fights--and that's what happened. The experimenters ranked the conflicts on a five-point scale, with one being a single cross word and five being a full-blown brawl. The next year, they went to the same children's schools to observe them at play and interview their teachers. Almost universally, the kids who practiced the best conflict-resolution skills at home carried those abilities into the classroom. Certainly, there are other things that could account for what makes some kids battlers in school and others not. But the most powerful variables--parents and personality--were identified and their influence isolated during the course of the two-year-long observations. Socioeconomic status, an X factor that bedevils studies like this one, was controlled by selecting all the families from the same economic stratum. Distill those influences away and what is left is the interaction of the sibs. "Siblings have a socializing effect on one another," Shaw says. "When you tease out all the other variables, it's the play styles that make the difference. Unlike a relationship with friends, you're stuck with your sibs. You learn to negotiate things day to day."