Love at first sight?

Memo to our male readers: The world is full of cognitive dissonance and distractions-so when it comes to impressing the ladies, fellas, timing can be crucial. And yes, eye contact is important too. In fact, cultures that frown upon eye contact as sexually provocative may have a point.

Evolutionary psychologists have found evidence that ovulation heightens women's response to the pheromone androstenol-a contributor to male body odor-and to the sight of strong male facial features, ones that emphasize secondary sex characteristics, such as an angled chin or a large forehead. But the increased appeal of attributes conveying a sense of strength, aggression or dominance is only one part of the finely tuned mate-identification system.

C. Neil Macrae, a professor of psychological and brain sciences at Dartmouth College, and his colleagues theorized that women's heightened awareness of male features during certain phases of their menstrual cycle might be further demonstrated by subtle tests related to person perception-for instance, asking women to assign a gender to a face in a photograph or to a stereotypical term such as bald, doll or skirt.

Macrae's study, published in the November 2002 issue of Psychological Science, tested women during...