Hot on the heels of a controversial book arguing that voters choose a candidate based on how he or she makes them feel—issues and position papers be damned—comes a study that’s enough to make you yearn for the good old days of monarchy: by measuring people’s unconscious judgments of an unfamiliar face, you can predict the outcome of elections 70 percent of the time.

Princeton psychologist Alexander Todorov and his student showed several dozen volunteers pairs of photos of unfamiliar faces, and asked them to choose, based on gut feelings alone, who was probably more competent. His earlier research had shown that people make judgments about someone’s trustworthiness, competence, aggressiveness and other traits in a mere one-tenth of a second. Now, in a study published online Monday in Proceedings of the National Academy of Sciences, he goes one depressing step further: these lightning-quick facial judgments can accurately predict real-world election results.

This time, in a study done two weeks before the 2006 elections, the pairs of photos were (unbeknownst to the participants) of the two frontrunners in either a gubernatorial or a U.S. senate race. (If a participant recognized either of the two faces, that pair didn't count.) “We never told our test subjects they were looking at candidates for political office. We only asked them to make a gut reaction response as to which unfamiliar face appeared more competent,” said Todorov.

When election night '06 arrived, the scientists compared the competency judgments with the results from the ballot box. The judgments predicted the winners in 72 percent of the senate races and 69 percent of the gubernatorial races. “This means that with a quick look at two photos, you have a great chance of predicting who will win,” Todorov said. “Voters are not that rational, after all.”

The assessment of competence doesn’t seem to be culture-specific. Other research, by political scientist Chappell Lawson of the Massachusetts Institute of Technology, finds that Americans can predict the outcome of elections in Mexico based on the same gut reactions. “Our findings surprised us, because Mexican politicians often emphasize very different aspects of their appearance, such as facial hair, which American political figures avoid,” said Lawson. “But Americans could still pick out the Mexican winners.”

What’s not clear is how this works when the faces you’re assessing are not anonymous, but those of pols you know. In that case, the assessment of competence—even when it’s made in one-tenth of a second—is likely (hopefully?) affected by what you know about the candidate. If so, then simply scanning the line of faces at the next presidential debate and deciding who looks most competent might not necessarily serve as a crystal ball for November ’08.

Just in time to think long and hard about your sunscreen options for next summer—or a tropical vacation this winter—comes a study suggesting that, to the truly hip, a dab of blinding white zinc oxide will be so last year. Bring on the green broccoli extract!

Slathering on an extract of broccoli sprouts, find scientists at Johns Hopkins University, can protect against the damaging effects of ultraviolet radiation. (Hey, don’t knock broccoli sprout extract. A clinical trial is currently studying whether it can prevent lung cancer in smokers.) Unlike sunscreens, which absorb UV and keep it from getting into the skin where it can damage DNA and thereby trigger skin cancer, a nice coating of broccoli sprout extract works inside cells. The result may be as good for your skin, cancer-wise, as a heaping helping of broccoli is for warding off other forms of cancer.

Skin covered with broccoli sprout extract and exposed to sunlight suffered much less inflammation and cell damage than bare naked skin, scientists led by Hopkins’ Paul Talalay are reporting this evening in the online edition of the Proceedings of the National Academy of Sciences. It wasn’t that the goop absorbed UV. Rather, it gets into your skin cells, boosting production of enzymes that protect cells against UV damage. That means the protection lasts for several days, even after the extract is no longer on your skin.

Interestingly, the protective compound in the broccoli sprout extracts is the same one, sulforaphane, that protects against several forms of cancer when you eat it. So if mom puts too much broccoli on your plate, rather than getting into a fight about throwing it away, preserve family peace by offering to smear it on your bod.

You know you feel lousy when you haven’t gotten enough sleep, but you probably didn’t know why—and neither did scientists. Although anyone who’s pulled an all-nighter or stayed up with a screaming baby or otherwise failed to get a good seven hours of shut-eye can testify to how grumpy they are the next morning, exactly what, in the brain, was behind that grumpiness was anyone’s guess. Now it can be told: your prefrontal cortex has gotten disconnected from your amygdala.

So find scientists who kept 13 healthy volunteers up for 35 hours straight, for one day and the following night and another day, and compared them to 13 similar people who slept during that intervening night. At the end of day two, all 26 had their brains scanned with functional magnetic resonance imaging (fMRI), while they were shown 100 images that fell along an emotional gradient from neutral to very upsetting, from images of leaves and wicker baskets to pictures of mutilated bodies, severed limbs and children with grotesque tumors.

In the sleep-deprived, seeing gruesome images led to a noticeable spike in activity in the brain’s amygdale, the structure that tags incoming information with an emotion, especially a negative one—labelling a sight or sound frightening or disgusting. On no sleep, the scientists from the University of California, Berkeley, and Harvard Medical School will report online tomorrow in the journal Current Biology, the amygdala goes into overdrive, and the usual braking mechanism is broken.

“It’s almost as though, without sleep, the brain had reverted back to more primitive patterns of activity, in that it was unable to put emotional experiences into context and produce controlled, appropriate responses,” said Matthew Walker, director of Berkeley’s Sleep and Neuroimaging Laboratory and lead author of the study.

Tracing the patterns of firing showed why. Usually, signals from the amygdala reach the prefrontal cortex and vice versa. Since the prefrontal cortex is the site of logical reasoning, it can take the amygdala’s terror and calm it down by pointing out that, say, the frightening sound coming from the ceiling is just branches blowing in the wind, or that a terrifying scene in a movie is just celluloid.

In sleep-deprived brains, the fMRI showed, the amygdala connects more strongly to the locus coeruleus. This evolutionarily-ancient part of the brain, rather than acting as an emotional brake the way the prefrontal cortex does, steps on the accelerator: it releases noradrenalin, ramping up the brain’s jumpiness and emotionality even further. “The emotional centers of the brain were over 60 percent more reactive under conditions of sleep deprivation than in subjects who had obtained a normal night of sleep,” Walker said. “It is almost as though, without sleep, the brain reverts back to a more primitive pattern of activity, becoming unable to put emotional experiences into context and produce controlled, appropriate responses.”

As a result, that friendly, reasonable co-worker turns into what he calls “emotional Jell-O” after an all-nighter, or else has to make a Herculean effort to rein in those emotions.

“You can see it in the reaction of a military combatant soldier dealing with a civilian, a tired mother to a meddlesome toddler, the medical resident to a pushy patient,” says Walker. Next step: figuring out how sleep deprivation cripples the emotional brain's connections to the rational brain.