Whom You’re Seen With
Psychology Today on “mate copying,” among the many elements of attraction:
To put it bluntly: The woman likes the taken guy more than the single guy. Mate copying has been documented countless times among non-human animals, but the body of empirical data confirming its existence in humans is rapidly growing.
[Further,] there is a strong theoretical reason for believing it occurs more frequently among females. Specifically, it solves a more important adaptive problem for females than for males—getting information about a potential partner. Because men are often initially concerned with the attractiveness of a partner, they can look at a female and instantly discern a fair bit of mate-relevant information. That’s often less the case for women.
When it comes to evaluating others, we don’t know what we don’t know. But what we do know is what we see, and seeing a potential mate succeed at attracting mates tells us much about that potential mate’s value.