Smooching feels good, of course, but couples first started swapping saliva as a way to test out genetic compatibility.
Tryptophan's sleepy effect is maximized by foods heavy in carbs.
The time of year when you were born may affect your neurochemistry.
If you've read or heard the news you've probably heard about a drug called ecstasy, or "e" for short. What is ecstasy and what does it do to your brain?
Everyone has experienced the queasy sensation. Yet scientists actually know very little about what causes nausea.
Ever feel sleepy after a big lunch? Find out the science behind taking a siesta!
After more than 20 years of smoking, I'm trying to quit. But instead of feeling good, I'm feeling sad, even depressed. What's going on?
Do you get sleepy on Thanksgiving and blame the turkey? Well, you're wrong to do so!
Why do some doctors give antidepressants, but not diet pills, to overweight patients?
Ever wonder why you become sleepy after a big meal? Find out on this Moment of Science.