Have you ever wondered why some people love to be scared? People who are first in the queue when a new horror movie is released, for instance. Or those who like nothing better than riding the scariest rollercoasters and extreme theme park rides. Or adrenalin addicts who quite happily leap off cliffs or tall buildings?
It's all caused by a brain chemical called dopamine, say American And Chinese researchers whose study is published in the journal PLoS One. Dopamine is linked with pleasurable things like falling in love, listening to great music and eating chocolate, and is produced in part of the brain that's often referred to as the reward centre.
But while good experiences boost your brain's production of dopamine, so too can bad experiences that evoke fear, say the scientists.
By studying lab mice, the scientists discovered all of the dopamine neurons in the ventral tegmental area of the brain responded to both good and bad experiences. Fear activated about 25% of the neurons too, boosting dopamine production even higher.
Your genes, however, may have an impact on quite how many dopamine cells are activated when something scary happens - which may help explain why some people are thrill-seekers while others prefer to play it safe.
The scientists still don't know how eating chocolate or watching horror movies boosts dopamine production in the brain. But their research could help shed some light on why some people become addicted to drugs and other risky behaviours, they say.
Do you get a thrill from having a fright?