Genetics are a big part of it, like you would expect, but its a bit more nuanced than what we learned in high school biology.

Studies have suggested that the contrast between the white of human eyes - known as the sclerae - and the colourful irises allows others to detect the direction of our gaze. The ability to detect gaze ...

You’re not alone if colder weather and longer nights make you feel down. This well-known phenomenon, called seasonal affective disorder (SAD), might explain why people feel low, irritable, and ...