WOMEN can work out if a man will make a good father just by looking at his face, new research reveals. Even studying a photograph gives them subconscious clues that he likes children and is therefore a good long-term partner.
Scientists behind the discovery believe it adds an important dimension to knowledge about mate selection among humans.
They say women judge a man on his genetic quality as well as his willingness to be a good parent for her offspring.
And their studies show keen ladies use masculine features as a guide to genetic quality.
When at their most fertile, they are especially attracted to men with features such as strong jaws.
But at other times of the month women prefer more feminine faces as softer features suggest a man will be a good long-term partner and help care for any children.
Researchers at St Andrew's University have even come up with the face of the perfect man, whose softer, more feminine features reflected a more nurturing side.
They concluded that the ideal partner should have a symmetrical face, large deep and expressive eyes, a straight nose and soft jaw.
A team from the University of California, Santa Barbara, took it a step further and analysed how accurate women were at reading a man's face for clues to testosterone levels and interest in children.
First they took 39 men aged 18 to 33 and tested their hormone levels.
The men were shown pairs of adult and infant faces and had to say which they found most appealing. This was designed to show whether they had a natural liking for children.
A group of 29 women aged around 18 were then given snaps of the men and asked to rate them.
They were told to point out if they thought each male liked children, was masculine, physically attractive or kind.
They also rated how attractive they would be as a short-term partner and a long-term mate.
The study, published today in the journal Proceedings of the Royal Society B: Biological Sciences, showed women were able to spot which men liked babies.
Those who women considered would be good with older children also scored highly on the baby affinity test.
Likewise they pointed out which men had the highest testosterone levels, as they tended to rate them as more masculine.
As expected, they found the masculine faces more attractive as short-term mates.
Intriguingly, even though all the men were asked to make a neutral expression for the photos, women thought those who liked children looked happier than those who did not seem interested.
Northumbria University evolutionary psychologist Dr Nick Neave said: "It seems that women can tell an awful lot from a man's face.
"The paper is a step forward in our understanding but it does not go all the way to answering questions about just what makes someone a good parent or perfect partner."