I was searching for a lost reference because of a tweet I made concerning eye contact behavior of men and women in a crowd setting. I ended up reviewing articles about facial attractiveness.
This is largely based on (Fink & Penton-Voak, 2002) who make a review and critique of literature about facial attractiveness markers and tries to offer evolutionary explanations for those markers. The three markers discussed are symmetry, averageness, and nonaverage sexually dismorphic features (hormone markers). Although we know attractiveness is influenced by culture, markers studied here have been found constistenly and cross-culturally.
Symmetry is hypothesized to indicate the ability to resist environmental perturbation during development. It is shown to be associated with genetic heterozygosity, (def. from the article: "the presence of different variants of a gene on homologous chromosomes"). Symmetry may thus be a cue for outbredness (the opposite of inbredness) and natural ability to resist parasites according to genetic diversity. However, a study by (Scheib, Gangestad & Thornhill 1999) was able to reproduce results of other symmetric facial studies by showing only the left side or right side of people's faces. This suggest symmetry might be covariating with other desirable or (negatively) with undesirable features.
Averageness is also a marker of heterozygosity for some hereditary traits. It has been observed by studies using computers to generate facial averages from multiple faces which scored almost always a higher rating than the faces the image was built from. The effect of averageness is rather unclear as studies like (Halberstadt & Rhodes 2000) observed averageness as an attractiveness indicator to non-facial objects (in this case, watches and drawing of animals). Averageness could be linked to other perceptual factors.
Feminine features are pretty straight forward. The smoothness of skin is showed to be an attractive factor for male, as for hairlessness and other obvious things such as lack of acnea, scars, moles, etc. For males, a high testosterone level is associated with protruded eye brow bones, a longer lower facial bone and also wider cheekbones, mandible and chin. Although some studies showed these features to be attractive for females, other studies had more mixed results. (Perrett et al. 1998) indicates women also associate masculine facial features with personality traits such as "less warm, less honest, and more dominant" (from the article) . Women self rated as physically attractive have a higher preference for masculine features when compared with women self rated as unattractive (Little, Burt, Penton-Voak, & Perrett, 2001). Another study arrived at the same findings using waist-to-hip ratio rather than self reported physical attractiveness.
What makes the issue even more complex is that female attraction to masculine traits seem to be variable according hormonal change during menstrual cycle. Women are more prone to be attracted to masculine facial features during ovulation. This cycle is accentuated for females scoring low psychological "masculinity" (Johnston et al. 2001) as well as for females currently in relationships or females looking for short term relationships. (Gangestad, Simpson et Al. 2004) observed women were more attracted to the scent of men with masculine and symmetrical faces during ovulation. So far, scientific literature seems to show that a woman's preferences are influenced by the ratio of estrogen and progesterone circulating in her bloodstream.
The paper I saw many years ago observed that men look for attractive women while women look for 'husky' men looking at them, husky being defined as high chest-to-waist or shoulder-to-waist ratio. While I was not able to find this article, (Anderson et Al, 2010) does confirm that women do look back at attractive males. However, they also did very poor job at memorizing those males afterwards. This is behavior also stronger during ovulation cycle. I'd like to go into physical attractiveness but it's even more complex and time consuming.
References
Evolutionary Psychology of Facial Attractiveness
Bernhard Fink1 and Ian Penton-Voak
Current Directions in Psychological Science. 11(5):154–158, OCT 2002
Women's Preferences for Male Behavioral Displays Change Across the Menstrual Cycle
Steven W. Gangestad, Jeffry A. Simpson, Alita J. Cousins, Christine E. Garver-Apgar, P. Niels Christensen
SAGE journals - psychological science
Volume: 15 issue: 3, page(s): 203-207
Issue published: March 1, 2004
Facial attractiveness, symmetry, and cues to good genes
Scheib JE, Gangestad SW, Thornhill R (1999)
Proceedings of the Royal Society of London, B 266: 1913–1917.
The Attractiveness of Nonface Averages: Implications for an Evolutionary Explanation of the Attractiveness of Average Faces.
Halberstadt, J., & Rhodes, G. (2000)
Psychological Science, 11, 285-289.
Effects of sexual dimorphism on facial attractiveness.
Perrett DI, Lee KJ, Penton-Voak I, Rowland D, Yoshikawa S, Burt DM, Henzi SP, Castles DL, Akamatsu S.
Nature. 1998 Aug 27;394(6696):884-7.
Self-Perceived Attractiveness Influences Human Female Preferences for Sexual Dimorphism and Symmetry in Male Faces.
Little, A. C., Burt, D. M., Penton-Voak, I. S., & Perrett, D. I. (2001).
Proceedings of the Royal Society of London B, 268, 39-44.
Male facial attractiveness: evidence for a hormone-mediated adaptive design.
Johnston V. S., Hagel R., Franklin M, Fink B & Grammer K
Evol. Hum. Behav. 22, 251-267.
Women’s preferences for male behavioral displays change across the menstrual cycle
Gangestad, S. W., Simpson, J. A., Cousins, A. J., Garver-Apgar, C. E., & Christensen, P. N. (2004).
Psychological Science, 15, 203–207.
I only have eyes for you: Ovulation redirects attention (but not memory) to attractive men
Uriah S.Andersona, D.Vaughn Beckerb, Joshua M.Ackermanc, Jenessa R.Shapirod, Steven L.Neuberga, Douglas T.Kenricka
Journal of Experimental Social Psychology
Volume 46, Issue 5, September 2010, Pages 804-808