Scientists explain the fear of great white sharks 06:34. Scientists in California are researching what makes people so scared of sharks. They believe the 1975 movie "Jaws" caused a generation of ...

Clowns can be unpredictable, inscrutable and a little weird. Those are just a few of the reasons why some people develop coulrophobia, or fear of clowns.

In human history, fear kept us safe when running from predators and anxiety kept us from going back to that lion-infested area. But what happens when these feelings get out of hand in humans today?

Uncertainty is part of everyone's life. People with this fear of the unknown may try hard to seek certainty and may find it emotionally difficult when they experience uncertainty. Learn more.