Studies on Physical Attractiveness, Symmetry, and Reproductive Success
Study 1: Facial Attractiveness, Symmetry, and Cues of Good Genes
Source: Scheib, J. E., Gangestad, S. W., & Thornhill, R. (1999). Proceedings of the Royal Society B.
DOI: 10.1098/rspb.1999.0866
Overview
This study explores whether women use facial symmetry as a primary cue for male attractiveness or if symmetry correlates with other traits signaling genetic quality. It tests the “good genes” hypothesis, which posits that females prefer mates with traits indicative of health, fertility, and disease resistance.
Objectives
1. Assess whether women can accurately perceive facial symmetry.
2. Determine if symmetry predicts attractiveness when symmetry cues are minimized.
3. Identify other traits (e.g., facial masculinity) correlated with symmetry and attractiveness.
Methodology
• Participants: 79 female undergraduates from the University of California.
• Materials: Standardized black-and-white photos of 40 male faces, digitized and measured for symmetry and masculinity (cheekbone prominence, lower face length).
• Procedure:
• Women rated full faces and half faces (left or right) for attractiveness or symmetry on a 7-point scale.
• Half-face ratings tested attractiveness without symmetry cues.
• Analysis: Pearson correlations between attractiveness ratings, symmetry, and masculinity, controlling for age.
Key Findings
• Symmetry and Attractiveness:
• Facial symmetry positively correlated with attractiveness ratings for full faces.
• Women could not accurately judge symmetry when directly asked.
• Attractiveness ratings of half faces (lacking symmetry cues) still correlated with symmetry, suggesting other cues drive perceptions.
• Facial Masculinity:
• Masculinity (prominent cheekbones, longer lower face) correlated positively with symmetry and attractiveness for both full and half faces.
• Masculinity may serve as a proxy for symmetry and phenotypic quality.
Conclusions
• Women do not consciously assess facial symmetry but use correlated traits like masculinity to judge attractiveness.
• Symmetry influences attractiveness indirectly through visible features, supporting the good genes hypothesis.
• Facial masculinity, linked to developmental stability, may signal genetic fitness.
Implications
• Evolutionary psychology: Women’s mate preferences prioritize traits signaling genetic quality, even subconsciously.
• Mate choice: Subtle facial features (e.g., cheekbone prominence, jaw proportions) may reflect hormonal or developmental health, influencing reproductive decisions.
Study 2: Visible Skin Condition and Perceptions of Male Facial Appearance
Source: Fink, B., Bunse, L., Matts, P. J., & D’Emiliano, D. (2012). International Journal of Cosmetic Science.
DOI: 10.1111/j.1468-2494.2012.00724.x
Overview
This study investigates whether cheek skin condition independently predicts perceptions of male facial age, health, and attractiveness, extending prior research focused on women.
Objectives
• Examine if cheek skin appearance (isolated from facial context) influences judgments of:
• Perceived age
• Health
• Attractiveness
• Assess the role of skin color homogeneity in social perceptions.
Methodology
• Participants: 160 Caucasian British men (aged 10–70).
• Materials: Digital facial images; isolated cheek skin patches from a prior study.
• Procedure:
• 301 raters (147 men, 154 women; mean age ~23) assessed full facial images for age, health, and attractiveness.
• Ratings compared to prior ratings of isolated cheek skin patches.
• Analysis: Correlations between cheek skin ratings and full-face perceptions.
Key Findings
• Skin Condition and Perceptions:
• Cheek skin ratings accurately predicted full-face judgments of age, health, and attractiveness.
• Uneven skin tone (decreased color homogeneity) was associated with:
• Older perceived age
• Lower perceived health
• Reduced attractiveness
• Independence of Skin Cues:
• Skin condition influenced perceptions independently of facial shape or other features.
Conclusions
• Skin color homogeneity is a robust signal of youth, health, and attractiveness in men.
• Skin condition plays a critical role in social judgments, beyond traditional cues like symmetry or masculinity.
Implications
• Cosmetics and Dermatology: Enhancing skin tone evenness in men can improve social perceptions, with applications in skincare product development.
• Evolutionary Psychology: Skin condition signal underlying health and genetic quality, influencing mate choice and social interactions.
Study 3: Physical Attractiveness Influences Reproductive Success of Modern Men
Source: Prokop, P., & Fedor, P. (2011). Journal of Ethology.
DOI: 10.1007/s10164-011-0274-0
Overview
This study tests whether physical attractiveness and height—indicators of genetic quality—predict marriage likelihood and reproductive success (number of offspring) in modern men, accounting for marital status.
Objectives
• Test two hypotheses:
1. Facially attractive and taller men are more likely to marry.
2. These men have higher reproductive success (more children).
• Examine if attractiveness influences reproduction beyond marriage.
Methodology
• Sample: 499 Slovakian men (mean age ~46), including single, married, and divorced individuals; retrospective photos at age ~20.
• Data Collection:
• Facial attractiveness rated by 27 female students (scale 1–7).
• Self-reported data: height, marital status, number of children, education, birth order, siblings.
• Analysis:
• Multiple logistic regression for marriage likelihood.
• Multiple linear regression for reproductive success, controlling for marital status.
Key Findings
• Marriage Likelihood:
• Taller and more attractive men were more likely to be married.
• Lower education was associated with being unmarried.
• Reproductive Success:
• Married men had significantly more children than single men.
• Facial attractiveness positively predicted number of offspring, even after controlling for marital status.
• Height influenced marriage.
• Other Factors: Birth order and number of siblings showed no significant effects.
Conclusions
• Physical attractiveness and height enhance marriage prospects, with attractiveness further increasing reproductive success.
• Attractiveness may confer reproductive advantages within marriage (e.g., higher fertility) or through extra-pair reproduction.
• Results support sexual selection theory, suggesting women prefer traits signaling genetic quality (health, immunity).
Implications
• Evolutionary Biology: Physical attractiveness remains a key factor in sexual selection, even in modern societies with contraception.
• Social Dynamics: Height and attractiveness influence mate choice and social status, impacting reproductive outcomes.
Synthesis of Findings
• Common Theme: All studies highlight the role of physical traits (symmetry, skin condition, attractiveness, height) as signals of genetic quality, influencing mate choice and reproductive success.
• Evolutionary Context: Traits like facial masculinity, skin homogeneity, and height reflect developmental stability, health, and hormonal profiles, aligning with the good genes hypothesis.
