Humans

Primatologist Isabel Behncke Izquierdo explains how bonobos learn by constantly playing. She says play isn't frivolous; it appears to be a critical way to solve problems and avoid conflict.

When Jane McGonigal was bedridden after a concussion, she gave herself a prescription: play a game. She says games helped her get better, and for many of us, virtual games can improve our real lives.

Why is it so hard to feel empathy for strangers? Because we're stressed by them, says neuroscientist Jeff Mogil. His research suggests one way to reduce that stress: play Rock Band together.

Psychologist Mihaly Csikszentmihalyi says we can achieve one of the most elusive needs — self-actualization — by finding a state of "flow" in our work or our hobbies.

What do we know about one of our most basic needs: sleep? Not a lot, says circadian neuroscientist Russell Foster. We know we need to do it to stay alive, but much about it remains a mystery.

It took 15 years and 250 million vaccines, but this week, health authorities officially declared North America and South America free of rubella — a virus that can cause severe birth defects.

A woman who caught pneumonic plague in Colorado last summer likely contracted it from her friend or his dog. Antibiotics limited the outbreak to four people and cured them.