A curious shift occurs during and right after a war: more boys tend to be born than girls. It’s been documented for decades in many nations, especially during long conflicts with many troops deployed. The cause of this boy boom has long flummoxed thinkers and scientists. Ideas have veered from the theological—a divine call for new men to replace those lost in battle—to the coital—returning soldiers have lots of sex, and so will be more likely to fertilize at a time in their ladies’ cycle that’s ripe for making boy babies.

I challenge you: Name one fact you still remember from the last test for which you crammed.

Anyone? Any fact?

Geneticists announced last week in the journal Nature that they have sequenced the complete set of DNA for three people—a Nigerian man, a Chinese man, and a Caucasian woman with leukemia—bringing the total number of individual genomes sequenced and published to five. (The first two are those of the genetics pioneers J. Craig Venter and James Watson.)

Mancini is my grandfather’s surname, and what a goose chase it’s been to find the Italian village from which his forebears hailed. Grandpa doesn't know its name because he was never told. Great-aunt Liz simply forgot. Finally, I got a tip from a friend of the famiglia who once hung around my late great-uncle “Tweet’s” luncheonette. The village was called Fontanelle. But which Fontanelle? Google Maps turned up two candidates of the same name, separated nearly 350 miles.

Whether you call it a hunch or vibes, a reckoning or a feeling in your bones, humans know the power of a nagging suspicion. Malcolm Gladwell’s Blink stands as testament to the fact that snap decisions often turn out much smarter than those following a thorough think. Now, neuroscientists say they’ve not only proven what they call “subliminal learning” scientifically, but have found the brain area involved.