In fact, men with wider faces are more likely to sacrifice for their team, according to the study, published online May 23 in the journal Psychological Science. The findings suggest that people’s first impressions of macho men — that they’re uncooperative, cold and even dishonest — aren’t so accurate. …

Exposure to high testosterone levels in the womb may bestow men with more “masculine” faces, manifesting in prominent jawlines and small eyes. These differences become clear at puberty, when testosterone levels rise in boys and their faces mature. Because testosterone is associated with aggression, some research has linked wide faces with the kind of guy who is always spoiling for a fight. …

The findings reveal that masculine traits can come out in both pro-social and anti-social ways. In other words, masculine guys may be more aggressive in general, but their manly characteristics are downright warm-and-fuzzy in some circumstances, such as when they need to support the home team.