Every guy who has attempted to go beyond first base on a date knows that the first kiss a woman gives him tells her all she needs to know about him as a possible partner.
The research supports this. Remarkably, this kind of attachment is not exclusive to humans. Foxes lick each other's faces, elephants put their trunks in each other's mouths, and bonobo chimpanzees kiss on the lips to show love for one another.
So why does our species kiss, and what biological, psychological, and physiological factors underlie this behaviour?
Is there a special technique for kissing a lady that will make her think of you every time she closes her eyes?
There are many hypotheses as to why we kiss (one study claims that social kissing was first practised by Medieval knights as a way to determine whether or not their wives had been drinking
while they were away fighting), but the most widely accepted scientific explanation is that humans kiss in order to find a compatible romantic partner.