UK scientists say that looking at a pretty face is enough to start the brain buzzing within seconds.
They have found that when someone sees an attractive face, their brain's "reward centre" lights up.
Bonding
The scientists believe bonding with attractive people is built into the brain.
Fact File
Brain science
The eye sees everything upside down until the brain turns it the right way
An ostrich's eye is bigger than its brain
90% of the brain is water
Studying the way you think and behave is called 'psychology'
Knut Kampe, of University College, London, led the testing.
Mr Kampe said that, from a nature point of view, it is important to rate someone as attractive because this signals things like health and strength. These qualities can be important when finding a partner.
This could help explain why people make very strong judgements the first time they see someone.
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A good-looking vote
