Anthropologist Robin Dunbar believes the evolutionary structure of social networks limits us to 150 meaningful relationships at a time — even with the rise of social media.
The National Academies of Sciences, Engineering and Medicine sorted through 10,000 studies to determine the good and bad health effects of marijuana. Tight drug restrictions impede research, they say.
After years of drought, California is getting drenched with rains. Some scientists and farmers are testing a way to capture that water by filling the state's depleted groundwater aquifers.
Killer whales are one of only three species known to have menopause. Researchers are looking at the conflict and cooperation between older and younger female whales to understand why.
This new knot has eight crossings, far more than previous molecular knots. The "rope" is very short — just 192 atoms long, or 500 times smaller than a red blood cell.
When scientists activate hunting circuits in the brains of genetically modified mice, the animals attack insects and even bottle caps as prey. It gives clues to the evolution of hunting in humans.
A new analysis of U.S. health insurance claims is worrisome, pediatricians say: More and more young people are being diagnosed with Type 2 diabetes, high blood pressure and sleep apnea.
New Yorker writer Michael Specter discusses emerging biotechnologies that will make it possible to remove disease and change the characteristics of life by rewriting the genetic code in cells.
A new NPR/Ipsos poll shows many Americans don't know details about the Affordable Care Act. And only 1 in 7 favors repealing the law altogether without a replacement.
A statewide collaborative of nail salons now has 120 members; all have made ventilation upgrades and switched from toxic products to safer ones. Will clients be willing to pay extra to help workers?