Do evolutionary psychologists often miss the forest for the trees when it comes to studies of physical attractiveness?Yes, argues a new paper in The Leadership Quarterly entitled "Beauty is in the In-Group of the Beholded: Intergroup Differences in the Perceived Attractiveness of Leaders" that I wrote along with Brian Wansink, Vlad Griskevicius, and David Sloan Wilson. In a sentence, we present two studies where we find that -- when partisan-affiliated group members rate familiar political leaders' physical attractiveness, their perceptions are colored by whether a given leader is part of their in-group or a rival in-group.In contrast with a focus on naturalistic environments where familiarity exists, evolutionary psychologists tend to be best known for studying the various fine-grain traits that contribute to whether people are considered physically attractive or not. Waist-to-hip ratio, facial symmetry, pupil dilation, relative leg length, ... the list goes on with respect to measurements that prior evolutionary research has highlighted as attractive or not.In the big picture, it makes sense that evolutionists would be interested in attractiveness since -- in a freely associated mating market, at least -- it's reasonable to assume that attractiveness contributes to a person's reproductive fitness. A fundamental problem or limitation, though, of the lion's share of evolutionary research on physical attractiveness has been its traditional reliance on strangers' ratings of strangers. Or, in some cases, strangers rating mannequins, magazine photos, or line drawings.Focusing on very specific traits with respect to attractiveness is helpful for "carving nature at its joints" and isolating measurements that wouldn't necessarily be considered to be relevant factors. That focus on "trees," though, such as waist-to-hip ratio -- to name one of the most famously studied variables -- can sometimes come at the expense of recognizing the figurative "forest."The new paper, which builds partly on an earlier Evolution and Human Behavior paper with D.S. Wilson on "The Effect of Nonphysical Traits on the Perception of Physical Attractiveness: Three Naturalistic Studies", aims to offer a corrective to the over-reliance on strangers' ratings of strangers with respect to physical attractiveness.Evolutionists broadly accept that humans evolved in relatively small groups where familiarity would be feasible for almost anyone in the community. It's only sensible, then, that evolutionary studies of physical attractiveness should pay closer attention to the importance of ratings of physical attractiveness among familiars.In fact, "ironic" seems to accurately and partly apply to the tendency for evolutionists to study reductionist components of physical attractiveness. The tendency might be due to the challenges of studying attractiveness in naturalistic environments. For example, it takes lots more effort to gain ratings from working professionals than, say, undergraduate students enrolled in a psychology subject pool.The large differences that exist between familiars' ratings of others' attractiveness and strangers' ratings, though, makes it clear that the extra effort is warranted or, at least, worth acknowledging as a limitation for "stranger studies."References CitedKniffin, K. M., Wansink, B., Griskevicius, V., and Wilson, D. S. Beauty is in the In-Group of the Beholded: Intergroup differences in the perceived attractiveness of leaders <>. The Leadership Quarterly, in press.Kniffin, K. M., and Wilson, D. S. 2004. The Effect of Nonphysical Traits on the Perception of Physical Attractiveness: Three naturalistic studies <>. Evolution and Human Behavior, 25: 88-101.