Deeply rooted in biology, our sense of what is physically appealing, and what is not, evolved over thousands of generations of human history. Although the concept of beauty may seem subjective—the eye of the beholder and all that—our perceptions of attractiveness, according to decades of research in evolutionary psychology, were shaped in part by natural selection in response to important cues that signal health, vitality, and reproductive fitness. When we find a face attractive, we are unconsciously assessing it for signs of health and genetic fitness.
Specific biological features suggest that an individual might have been able to thrive in harsh, often resource-poor, ancestral environments. Even though the modern landscape is markedly different from our ancestral past, we carry with us many of the same preferences for beauty that confer success in ancestral landscapes
We Judge Attractiveness Using Health Markers
The mate preferences we hold for beauty and sexiness are evolved adaptations designed to help us identify potential partners with the best chances of survival and reproduction. While small variations in standards of beauty exist between cultures and individuals, certain universal markers signal health and vitality, making them nearly universally attractive. Let’s look at four key biological markers that play a meaningful role in our perceptions of facial and body attractiveness: developmental stability, hormonal influences, indicators of age, and carotenoid pigmentation.
1. Developmental Stability (Physical Symmetry)
Facial symmetry is one of the most universally recognized markers of attractiveness. Symmetry refers to the balance and proportion of facial features on both sides of the face. Symmetrical faces are thought to be perceived as more attractive because they signal developmental stability, meaning that an individual has faced fewer genetic and environmental stressors during their development, leading to optimal health.
Researchers have shown that symmetrical faces are consistently rated as more attractive across different populations. According to this work, preferences for facial symmetry are consistent across cultures, suggesting that this is not merely a modern social artifact.
Symmetry is a proxy for good genes and a robust immune system. A symmetrical face indicates that an individual has successfully navigated the challenges of development, making them a potentially healthier and more viable mate. Asymmetry can result from genetic mutations, environmental stresses, or developmental disturbances. A symmetrical face suggests that an individual has experienced fewer of these negative influences, indicating good genes and overall health.
Over time, human brains may have evolved to prefer symmetrical faces because these preferences increased the chances of choosing a healthy, fertile mate. This preference for symmetry could be an evolutionary adaptation that enhances reproductive success.
2. Hormonal Influences (Estrogen and Testosterone)
Hormones play a pivotal role in shaping our facial features, and thus, our attractiveness. The two most commonly implicated hormones in this context are estrogen and testosterone. Research has shown that these hormone-driven features play a significant role in our perceptions of attractiveness. Elevated levels of these hormones produce markedly different effects on facial markers, which are often perceived as attractive due to their associations with fertility and health.
- Estrogen: In women, high levels of estrogen are linked to facial features such as a smaller chin, fuller lips, higher cheekbones, and larger eyes. These features are associated with youthfulness and reproductive potential. Estrogen promotes the development of these traits, making faces that exhibit them appear more feminine and attractive.
- Testosterone: In men, testosterone is associated with features like a pronounced jawline, a heavier brow, and more prominent cheekbones. These features are indicative of physical strength, dominance, and genetic fitness. Higher levels of testosterone are also linked to a strong immune system, which can make these masculine features more attractive to potential mates.
3. Senescence (Age and Neoteny)
The preference for youthful-looking faces can be attributed to the evolutionary association between age and reproductive potential. Neoteny, the retention of youthful features into adulthood, is often considered attractive because it signals vitality and health.
Research shows that cues to youthfulness, such as large eyes and a smooth forehead, are often associated with neoteny. Such features are attractive because they signal that an individual is in their reproductive prime. Therefore, maintaining a youthful appearance can enhance one’s attractiveness by signaling health and fertility.
Other indicators of age include skin quality, wrinkle formation, and the overall texture and elasticity of the skin. Smooth, clear skin is often perceived as a marker of youth and health. As we age, our skin loses elasticity and becomes more prone to wrinkles and other signs of aging, which can detract from perceived attractiveness.
4. Carotenoid Pigmentation (Gut Health)
Carotenoids are pigments found in various fruits and vegetables, and they play a significant role in determining skin coloration. Unlike some other markers of attractiveness, carotenoids are obtained exclusively through diet. That is, we don’t make any in our bodies; we find them and consume them in foods. These essential antioxidants help protect the skin and other tissues from damage.
Individuals with higher levels of carotenoids in their diet tend to have a slight yellowish tint to their skin, which is perceived as healthy and attractive. If you’ve got a lot of carotenoids—in fact, excess carotenoids—you put the extras in your skin. A healthy gut is necessary to be able to absorb carotenoids. Thus, the yellowness in all skin, no matter if it is light or dark, is a marker of carotenoids which indicates good gut health. Studies reveal that people with higher carotenoid levels are often rated as more attractive, likely because this pigmentation is an indicator of overall health and vitality.
Conclusion
Beauty is not merely about aesthetic appeal; it also involves a complex interplay of biological signals that guide our social and reproductive preferences. As research continues to uncover the intricacies of these markers, we gain a deeper understanding of why we find certain faces more attractive and how these preferences shape our interactions and relationships.
© Kevin Bennett, PhD, 2024
