A man with a "good face" may appear to be more honest but emotions go way beyond the face. It's all about context, especially with men who look like bad boys.

In previous studies, a broader face for a man was usually associated with more aggressive characteristics. Square jaw, a masculine outline and a stoic look were linked to a person viewing that wide face as dishonest, uncooperative and cold. Previous studies also associated broad-faced males as more likely to cheat or be deceptive. It turns out this assumption about broad-face men cannot be taken at face value as these bad boys can be quite selfless.

In a new study, led by Michael Stirrat, PhD, from the University of St. Andrews, men with wider faces were not always bad boys. Facial width is scaled in conjunction with facial height. Researchers gave students from the university money that could be used to benefit the individual or the group. The researchers told half of the students that the results would be compared with other students from the same university while the other half of the students were told that the results would be compared with a rival institution.

It turns out, when faced with competition, the wider faced males were totally cooperative with the greater good, sacrificing their portion of the money for the benefit of the group. At the mention of a rival, the wide face males were more cooperative than other males. When there was no rival present, the wide face males were less cooperative than other males.

Researchers believe that men cannot be so easily classified based on facial characteristics although some of those assumptions have been proven out in previous studies. It seems like men may be more in tune with the needs of a group and may be more susceptible to the effects of being observed.

This understanding of one trait being situational can help make sense of other studies. Recent studies of facial width in regards to male CEO, the wider the better as CEO's with wider faces were leading companies that were doing well financially while CEO's with narrower faces were at companies who were less successful financially. Depending on the situation, in this case running a business, a wide face male may be more committed to group success, leading to more self-sacrifice.

The study does not assume that all broad-faced men will act one way or another, but rather a man with a wider face may be more likely to act a certain way based on a given situation. While a wide face male may be physically aggressive or try to threaten you when they are not in your group, they may be the first one to lend a helping hand if you are in the same group.

The study was published in Psychological Science.