Women generally find calm, collected men more attractive, and scientists now suggest they know the biology of why that is.

Investigations into what makes men desirable often focus on testosterone. The hormone is linked with masculine facial traits, such as larger jaws and heavier brows, and is typically associated with better long-term health. As such, it might at first glance make sense from an evolutionary point of view if women found testosterone-laden men especially attractive.

However, past studies have often revealed that men with high testosterone levels are not automatically appealing to women, who view such testosterone-laden men as having long-term drawbacks. For instance, the macho guys may lead a “player’s” lifestyle, or may also be bad parents.

Instead, human behavioral ecologist Fhionna Moore at the University of Abertay Dundee in Scotland and her colleagues focused on the stress-linked hormone cortisol. Persistently high levels of cortisol can suppress not just the immune system, but also reproductive function. As such, it would make sense if women preferred men with low cortisol levels — that is, those who are not stressed out.

The whole article goes on to talk about how guys who are more laid-back, relaxed, and happy-go-lucky were generally found more attractive than “alpha male” types with high testosterone levels.  I think this comes down to a “looks vs. personality” debate.  Yes, the study was done based on looks, as in a “macho” looking guy vs. a “laid back” looking guy, but when it comes down to it, women prefer a man who has a personality that’s more conducive to what they enjoy, as opposed to a good-looking meathead.

Personality is always the great equalizer in attraction.  Looks fade, the novelty wears off, and when that happens, you’re just stuck with who the person is, and to a lot of women, that matters a great deal.