Autism = genes + environment

Based on what I’ve learned, it’s always seemed most likely to me that autism almost had to be a result of both genes and environment.  E.g., certain genes leave one vulnerable to certain environmental insults that lead to autism.  Unfortunately, we don’t really know what those environmental insults are.  Some new twin-based research suggests the environmental portion of this is much larger than previously thought:

Environmental factors play a more important role in causing autism than previously assumed and, surprisingly, an even larger role than genetics, according to a new study out of UCSF and Stanford that could force a dramatic swing in the focus of research into the developmental disorder.

The study, published in Monday’s issue of the Archives of General Psychiatry, looked at 192 pairs of twins in California and, using a mathematical model, found that genetics account for about 38 percent of the risk of autism, and environmental factors account for about 62 percent.

Previous twin studies had suggested that autism was highly inheritable, with genetics accounting for roughly 90 percent of all cases worldwide.

That’s quite an over-turning of the conventional wisdom.  I’ve always felt lucky that Alex’s autism is one of the few cases (Tuberous Sclerosis Complex) where we know it’s 100% genetic.  Not that it’s lucky he has autism, of course, but that we don’t face the uncertainty of so many parents. In some ways, this finding means only more anxiety for parents: 1) wondering what they did wrong in exposing their child to that lead to autism; or 2) becoming insanely hyper-vigilant to prevent those environmental insults of which nobody knows what they actually are.


Most of you have probably already read David Brooks’ brilliant takedown of the Tea Party yesterday.  Here’s the long, but most excellent key portion:

The members of this movement do not accept the logic of compromise, no matter how sweet the terms. If you ask them to raise taxes by an inch in order to cut government by a foot, they will say no. If you ask them to raise taxes by an inch to cut government by a yard, they will still say no.

The members of this movement do not accept the legitimacy of scholars and intellectual authorities. A thousand impartial experts may tell them that a default on the debt would have calamitous effects, far worse than raising tax revenues a bit. But the members of this movement refuse to believe it.

The members of this movement have no sense of moral decency. A nation makes a sacred pledge to pay the money back when it borrows money. But the members of this movement talk blandly of default and are willing to stain their nation’s honor.

The members of this movement have no economic theory worthy of the name. Economists have identified many factors that contribute to economic growth, ranging from the productivity of the work force to the share of private savings that is available for private investment. Tax levels matter, but they are far from the only or even the most important factor.

But to members of this movement, tax levels are everything. Members of this tendency have taken a small piece of economic policy and turned it into a sacred fixation. They are willing to cut education and research to preserve tax expenditures. Manufacturing employment is cratering even as output rises, but members of this movement somehow believe such problems can be addressed so long as they continue to worship their idol.

I’d planned to have more to say on the meta-meaning of this, but, hey, I’m actually on vacation, so all you’re going to get is a link to Jon Chait’s fascinating take and how this moment is somewhat like Cronkite finally coming out against the Vietnam war.  I wish.  The leaders of the Republican party have obviously long since stopped caring what sensible Republicans think about them.  Though, just maybe, this is a moment that can help lead us past the knee-jerk “bipartisan” “both sides are equally to blame” centrism of the Washington press corps.

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