Humans' compulsion to touch their faces may be part of a subconscious instinct to smell themselves.
By analyzing videos of dogs and horses playing together, researchers are finding clues about what they call "a universal language of play."
During this modern coronavirus pandemic, our ancient instincts for avoiding disease may misfire.
Female convict cichlid fish turned from optimists to pessimists when separated from their chosen partners.
Studies show the answer is complicated.