For according to scientists, people can tell in an instant whether someone fancies a quick fling or a life of commitment.
But as these computer-enhanced pictures show, the differences are so subtle that sometimes we might not even be aware of them.
"This book should have been written a long time ago, but it wasn't...
Just from the photographs, up to 72 per cent made fairly accurate guesses about who would be more interested in quick sex.
The study found that women open to one-night stands were usually seen as more attractive, while men most ready for casual sex were perceived by women as being more masculine-looking, with facial features including a squarer jaw, larger nose and smaller eyes.
A study of 700 heterosexuals found that men were generally attracted to women who they think are open to easy sex.
But women revealed they were usually interested in men as long-term partners.
According to the experts, if you strike up a conversation with the man or woman on the right you could end up in bed for a no-strings-attached one-night stand and never see each other again.
Volunteers working with scientists from Durham, St Andrews and Aberdeen universities were asked to assess photographs to decide what they thought was the model’s attitude towards sex.The results were then compared with the models’ actual attitudes.GAZE into the eyes of the couple on the left of these pictures and you should see the look of love.Glance at those on the right, however, and all you should be able to spot is pure lust.Enter your mobile number or email address below and we'll send you a link to download the free Kindle App.
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