5 Most Incredible Discoveries of the Week

The happiest kids in the world and pot-stunted short guys make the list:

• If You're Short (and Male), Your Bong May Be to Blame: If you smoked marijuana as a prepubescent boy, you may have lost 4 inches or so of height. Researchers studied growth hormone levels in the blood of boys addicted to marijuana, as well as in non-smokers. Researchers checked back in at age 20, and non-smokers were 4.6 inches taller on average than the smokers. The pot may have actually stressed their bodies out.

• Snakes Used to Have Ankles: Scientists putting together the most comprehensive family tree of snakes to date say the first ones had small hind limbs, complete with toes and ankles. Researchers believe the ancestral slitherer at the top of the family tree lived in the Southern Hemisphere about 128 million years ago. It hunted a little differently, too.

• Why Men Kill Themselves Far More Often Than Women: Male suicides outnumber female ones in every nation. And not by a little: In the world's most suicidal countries, the male suicide rate is often six or eight times the female rate. "Why?" is the main question, and part of the answer is "social perfectionism." But there's a lot more to this puzzle.
• Giant Pandas May Be Dying Out Because They're Eating the Wrong Thing: Pandas have been munching on bamboo for 7 million years, so it was a surprise when researchers analyzed fecal samples from 45 giant pandas and found gut bacteria not at all designed to process the animals' food of choice. Turns out their gut bacteria is meant to break down a very different edible.

• To Be Happy, Kids Don't Need Things (Say Kids): Most kids are happy regardless of material wealth, according to a new survey of 53,000 8- to 12-year-olds in 15 countries. But researchers discovered there are subtle differences across populations, and the results are somewhat surprising. In fact, Norway, which always seems to pop up on "best places to live" lists, doesn't do so hot on this one.

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