Now, it's easy to find how honest your partner is or how capable he is of cheating on you. A new study has found that a man's trustworthiness can be measured from the width of his face.
While men with a wider visage tend to be more devious and more willing to cheat, thinner-featured men are likelier to be honest and open.
According to Dr Michael Haselhuhn, who led the study at the University of Wisconsin-Milwaukee: "We demonstrate that men with wider faces feel more powerful, and these feelings of power lead directly to less ethical behaviour, including lying and cheating.
Hence, the study suggests that celebrities such as David Tennant and Hugh Laurie are trustworthier than womanising Jack Nicholson or potato-faced Wayne Rooney.
The discovery is reminiscent of phrenology, the Victorian belief that personal characteristics are revealed in the shape of the head. However, scientists say their findings are based on sound scientific experiments as well.
They conducted an experiment, wherein, 192 US business students took part in a role-playing game.
In pairs they took the parts of a house seller who will only agree to sell their home if it is preserved and a buyer who wants to convert the property into a hotel.
It emerged that men with broader faces were more likely to lie about their intentions than men with narrow faces. The study appears in the journal Proceedings of the Royal Society B.