Science behind beauty: How evolution leads to some people being

As humans we tend to admire beauty. We always have a checklist ready of what constitutes as beautiful and what does not. When asked where these checklist come from, we are prompt to reply as cultural beauty ideals or more recently, Western beauty ideals. A study show that six months old infant tend to stare longer at an adults who are perceived to be attractive by society than at an adults perceived to be unattractive. This shows we know beauty a lot before than culture and social norms enters in our lives. Therefore, we need to understand that there is a whole science to what is beautiful and why we are attracted to beautiful people. This science is known as evolutionary biology.

Why is beauty important?

In our frenzy to look constantly appealing we forget why we make efforts to look beautiful on the first place.

Reproductive success: The quest of looking beautiful started with evolution as humans look for mates to reproduce and pass on their genes to their offspring. For this it was necessary that the mate they select has to be strong for higher reproductive success. The most promising indicator to select the mate became the facial and bodily features, each one assessed and concluded whether the mate is fit for reproduction or not. There is a gender difference in looking for mates. Women look for men with resources and good genes to reproduce healthy children and provide for their children while men look for women with good genes to reproduce healthy children and share the resources with the woman and the child.

Halo Effect: This psychological effect comes in play where we take one trait about and it affects our impression about the thing. Simple example would be when we see a well-groomed person and attractive person; we form a mental impression that the person is good. Since this effect is applicable to brands, company or product also, we also need to know that ‘beautiful is good’ hypotheses exists where people believe that attractive people are perceived to have desirable traits such intelligence, kindness, good health and generosity as compared to less attractive people. This leads to people perceived as attractive  succeed more in comparison to people perceived as unattractive. 

 How our brain assesses attractiveness: The inferior occipital gyri (IOG) interpret movements on faces, such as eye gaze, lip movement and facial expressions. The fusiform face area (FFA) recognizes and processes the location of features on face, especially the eyes, nose, and mouth) and the spaces in between. Finally, the orbitofrontal cortex (OFC) judges the attractiveness of the person produces the neurological rewards (dopamine and other neurotransmitters) for finding it.

Let us look at how evolution leads some people be termed as beautiful and some people as not.

 Facial color and wrinkles

The skin is the largest organ of our body and the first skin we see is of the face. It is therefore important how the color of the skin is. It is generally seen that even skin tone signals health which increases attractiveness of the person. This might explain why we hate acne on us and others, which gives the person unhealthy appearance and lesser attractiveness. A finding across many ethnic groups, including Chinese, Caucasians, Latin Americans and South Africans show that people put direct correlation with skin colour with age and loses red tones as skin becomes darker with age. People often correctly assess ages when shown a patch of skin with wrinkles. Therefore, a skin with wrinkles and discoloration of skin signal aging and therefore the person is seen as unfit for mating and reproduction.

Faces and their features

Humans tend to be attracted to average faces and average facial features. In a study, multiple images were collected and composite faces were made out of them and they were rated more attractive than the individual faces which were used to make the composite faces (Langlois, Roggman and Musselman, 1994). The possible explanations given are that composite faces even out all the imperfections such as asymmetry and prominent features, which leads to familiarity and therefore less mental efforts to recognize and interpret attractiveness. Facial symmetry is affected by stress, genetic diseases malnourishment, lifestyle choices, aging and DNA defects.  This is the reason why symmetry is hardwired in our genetics as symmetry signals person being healthy and disease and asymmetrical features signals unhealthy. Therefore symmetry plays a big role in attractiveness and mate selection for reproduction.

Body Proportions

The sex hormones testosterone in men and estrogen in women largely determine the bodily and facial features, reshaping the male bodies with stronger jaw line, growth of beard, increase in shoulder-to-waist ratio while in women hips-to-waist increases, their breasts grow and their facial features become softer. The preferred body proportions for ratio of waist to hips for men of 0.9, and waist to hips for women of 0.7. The general perception is that people who are in ideal proportion are healthy and therefore fit for mating and attraction. However, culture plays a big part in the attraction as well where developing countries which has scarce food and other resources prefer overweight mate as it signals enough resources and health to reproduce whereas in developed  countries with enough resources people strive for healthy bodies as an indication of being disease-free.

Interestingly, foot size also comes in play as proportionately small foot in women is found attractive since women’s foot size tend to increase as they age and have children. A smaller foot indicates youth and reproductive possibilities. However it is seen that too small or too big feet are termed as unattractive also but dainty feet in women are seen as attractive.

Age Perception

Youth is major factor for assessing anyone’s attractiveness. The more the person appears youthful, the more they are perceived as likeable, desirable and fit for mating and reproduction. The body in its prime is perceived to be strong and healthy and therefore chances of higher reproductive success and healthier offspring. The age is typically assessed by condition of body, skin and hair.

It is interesting to know that since men accumulate wealth and resources as they age, they are termed more attractive even at an older age while women tend to be labeled as unattractive as she begins to lose fertility as they age.

Image Courtesy : Jessica_Alba_Cropped2.png: pinguino k from North Hollywood, USAderivative work: Tomwsulcer, CC BY 2.0 <https://creativecommons.org/licenses/by/2.0>, via Wikimedia Commons

The post ends here. In the next post, I will elaborate on how cultural practices are used for deception is used to project attractiveness and why they work.