Xylophagia, a condition that makes people want to ingest paper, is a form of pica A.K.A an appetite for non-food items.

While some people can't derive pleasure from music, others with hypersensitive hearing even find musical beats painful.

No one truly "multi-tasks" -- technically, people just "task-switch," but it appears as if they're performing different tasks simultaneously.

Circadian rhythms, our bodies' internal clocks, determine when we're most productive.

Surprises catch people unprepared and disrupt their routine; they also induce the feeling of losing control.

Resorting to humor activates the endorphin system in the brain, making it easier for people to withstand difficult situations.

Tickling can overwhelm the nervous system and cause actual, temporary paralysis -- which can terrify people who like to be in control.

Called anthropomorphism, the tendency to attribute human traits or intentions to non-living entities has been linked to social intelligence.

Disagreeing can feel "threatening to our relationships and that feeling of connectedness" humans are primed to cultivate.

"It turns out that we're hard-wired to believe that others are staring at us, especially when we're uncertain."

Face touching is an unconscious technique for managing stress and other emotions.

For people with social anxiety, hugging can make it worse.

A fear of being happy comes from a belief that happiness cannot be stable or constant, and that joy will lead to disappointment.

There are behavioral and physiological components to the need to cover ourselves with a blanket or sheet while sleeping.

Turns out, choosing the right pillow for your body and sleep habits is exceedingly complicated.

While some people's hatred of roller coasters stems from a fear of height, closed spaces, or vertigo — some also dread embarrassing reactions to the ride.

Tears are a natural response to intense emotions such as anger, though they're often misconstrued as weakness.

It's a kind of stress response called "learned helplessness" that renders the individual passive in the face of stress.