"The effects of facial masculinity and attractiveness fit in a larger picture that has emerged," says Garver-Apgar.
The prevailing wisdom during much of the last half-century was that women did not experience estrus, the period in which other primates signal their fertility with swollen genitals. But newer research suggests that women may not have lost all remnants of estrus.
Evolutionary biologists have documented that women are choosy when fertile, and their freedom to choose mates is increased because their fertile phase is not advertised as it is in other primates. A growing body of evidence suggests that, when most fertile, women gravitate toward males who show signs of good genetic quality.
Masculine facial features suggest that a man is of good genetic quality, because he had the resources during development not only to survive but also to expend energy on a macho visage. Rugged-looking jaws and eyebrows are signals of testosterone.
Instead of using his energy on other features or to maintain his immune system, the masculine-looking male may have had a "surplus energy budget," Garver-Apgar says.
During development, individuals make trade-offs. They can build big brains, large muscles or stronger immune systems. Brains, brawn and immunity may all compete for the same resources.
While it is not surprising that women's gazes would fall on masculine-looking men when they are most fertile, Garver-Apgar says the lack of a similar effect with intelligence is perplexing.
"That we didn't find any effect of men's intelligence on their partners' sexual interests across the cycle is important because some evidence suggests that intelligence associates with genetic quality."
But the data on the intelligence-attraction equation are mixed. If intelligence correlates with good genetic quality, Garver-Apgar wonders, why
|Contact: Christine Garver-Apgar|
University of Colorado at Boulder