How your brain decides what is beautiful | Anjan Chatterjee

Summary

In 1878, Sir Francis Galton introduced a technique to create composite portraits to identify criminality, unexpectedly finding beauty instead. This discovery sparked questions about the nature of beauty and its evolutionary and neurological roots. The script explores how factors like averaging, symmetry, and hormonal effects contribute to attractiveness, and how these traits signal health and fertility. It also delves into the automatic neural responses to beauty and the societal biases it can engender. The talk concludes by reflecting on how modern advancements are altering the traditional criteria for beauty.

Takeaways

• 🧠 Sir Francis Galton introduced a technique to create composite portraits from photographs to characterize different types of people, but found beauty in the composite of violent criminals.
• 💡 Galton's findings raise philosophical and scientific questions about what defines beauty and how evolutionary psychology and neuroscience are now contributing to the understanding of this concept.
• 🖼️ Research shows that average, symmetrical faces are generally considered more attractive due to their representation of genetic diversity and health indicators.
• 🔬 Symmetry in faces is often an indicator of health, as developmental abnormalities and parasitic infections can cause asymmetries.
• 💄 Maksymilian Faktorowicz, later known as Max Factor, recognized the role of symmetry in beauty and created tools to enhance facial symmetry with makeup.
• 👩‍🔬 Hormones like estrogen and testosterone shape features associated with beauty. Estrogen is linked with fertility signals in women, while testosterone shapes traditionally masculine features in men.
• 🦚 The handicap principle explains how features like a peacock’s tail or testosterone-infused traits in men serve as a costly display of fitness, despite seeming like evolutionary disadvantages.
• 👁️ Attractive faces activate both the visual cortex, specifically the fusiform gyrus, and reward centers in the brain, showing a connection between beauty and pleasure responses.
• 🤔 The brain automatically associates beauty with positive traits, like intelligence and goodness, which contributes to societal biases that favor attractive people.
• 🌍 Beauty standards, shaped over millions of years, are changing due to modern medicine and technology, relaxing the evolutionary filters and allowing more variation in what is considered attractive.

Q & A

Who was Sir Francis Galton and what was he known for?

Sir Francis Galton was a polymath known for his pioneering work in human intelligence. He was an explorer, anthropologist, sociologist, psychologist, statistician, and also a eugenist. In the talk mentioned, he presents his technique of creating composite portraits by combining photographs.

What surprising result did Galton discover when combining photographs of criminals?

Galton expected to discover a typical 'criminal face' by combining photographs of criminals. However, to his surprise, the composite portrait he produced was beautiful.

What does the concept of 'averaging' in facial attractiveness mean?

Averaging refers to the idea that composite or average faces, which represent the central tendencies of a group, are often found more attractive than individual faces. This is thought to be linked to greater genetic diversity and adaptability.

Why is symmetry considered important in facial attractiveness?

Symmetry is important because people generally find symmetric faces more attractive. Asymmetry can be associated with developmental abnormalities or health issues such as parasitic infections. Symmetry often indicates health and genetic fitness.

What roles do hormones like estrogen and testosterone play in shaping facial attractiveness?

Estrogen in women produces features like large eyes, full lips, and narrow chins, which signal youth and fertility, while testosterone in men creates features like heavier brows and square jaws, considered typically masculine. However, testosterone can suppress the immune system, and its presence suggests a 'handicap' that only fit men can afford.

What is the 'handicap principle' and how does it relate to attractiveness?

The handicap principle suggests that extravagant traits, such as the peacock's tail or masculine features in men (influenced by testosterone), signal fitness. Only especially healthy individuals can afford the 'cost' of maintaining these traits, which makes them attractive.

How does beauty affect the brain according to the script?

When we see attractive faces, parts of our brain, including the visual cortex, fusiform gyrus, and reward centers like the ventral striatum, are activated. These areas process visual beauty and link it to pleasure, suggesting an automatic, unconscious response to beauty.

What does the 'beauty is good' stereotype refer to?

The 'beauty is good' stereotype refers to the reflexive association between beauty and positive qualities like intelligence, kindness, and trustworthiness. This association occurs even when people are not consciously thinking about beauty or goodness.

How does facial disfigurement affect social perceptions, according to the script?

People with facial anomalies or disfigurements are often judged as less good, less intelligent, and less competent due to implicit biases. This 'disfigured is bad' stereotype is reinforced by media depictions of villains often having facial disfigurements.

How is modern technology changing the concept of beauty?

Modern medicine and technology are relaxing the biological filters that once determined reproductive success. With advances like antibiotics, surgery, and in vitro fertilization, the traits that signify beauty may be changing, allowing for more variability in what is considered attractive.

Outlines

00:00

🔬 The Discovery of Composite Beauty

In 1878, Sir Francis Galton, a polymath known for his work in various fields including eugenics, presented a technique to combine photographs to create composite portraits at the Anthropologic Institute of Great Britain and Ireland. Galton aimed to identify the facial characteristics of criminality by merging images of violent criminals but unexpectedly found the resulting composite to be beautiful. This led to profound questions about beauty and its perception. The narrative then shifts to modern scientific approaches, using evolutionary psychology and neuroscience, to understand beauty, particularly in human faces. Factors like averaging, symmetry, and hormonal effects are discussed as contributors to attractiveness, with averaging being linked to genetic diversity and adaptability, symmetry to health, and hormones to fertility signals in features.

05:01

🦚 The Evolutionary Paradox of Beauty

This section delves into the evolutionary perspective on beauty, focusing on the roles of estrogen and testosterone in shaping attractive features. It highlights the preference for youthful and mature indicators in women and traditionally masculine features in men. The irony is presented where testosterone, which can suppress the immune system, is associated with health and attractiveness through a 'handicap principle', drawing a parallel to the peacock's tail. The principle suggests that the ability to maintain such features indicates overall fitness. The discussion also touches on the idea that preferences for certain features can become universal over time due to their association with reproductive success, even if the initial preferences are arbitrary. The section concludes with a thought experiment illustrating how arbitrary preferences can evolve into universal traits within a population.

10:05

🧠 The Neural and Social Impact of Beauty

The final paragraph explores the neurological responses to beauty, explaining how attractive faces activate the visual cortex and pleasure centers in the brain. It describes experiments showing that the brain automatically responds to beauty, even when not consciously perceived. The 'beauty is good' stereotype is discussed, noting how the brain reflexively links beauty with goodness, which can influence social judgments and outcomes. The paragraph also addresses the negative stereotypes associated with facial disfigurements and the role of media in perpetuating these biases. It concludes with a forward-looking statement on the evolving nature of beauty, suggesting that as society and technology change, so too will the universal standards of beauty, reflecting a dynamic interplay between culture, biology, and environment.

Keywords

💡Composite Portraits

A technique introduced by Sir Francis Galton, where multiple photographs are combined to create a single image that represents common features of a group. In the video, Galton’s attempt to find the ‘face of criminality’ through composites of criminals leads to the surprising result of creating a beautiful face. This raises questions about the nature of beauty and how certain physical configurations evoke aesthetic responses.

💡Symmetry

Symmetry refers to the balanced proportions of facial features on either side of the face. In the video, symmetry is identified as a key factor in determining beauty. People tend to find symmetrical faces more attractive because asymmetry is often linked to developmental issues or poor health, suggesting that symmetry could be an indicator of good genetics or fitness.

💡Averaging

Averaging is the concept that combining multiple faces into a composite often results in a face perceived as more attractive than the individual faces. This phenomenon is linked to the idea that average faces represent the central tendencies of a population, which might signal genetic diversity and adaptability. The video uses this to explain why people tend to find mixed-race individuals attractive.

💡Evolutionary Psychology

Evolutionary psychology explores how human psychological traits are shaped by evolutionary processes. In the video, beauty is discussed through this lens, explaining that physical features such as symmetry and facial structure have been selected for over time because they contributed to reproductive success. Beauty is thus framed as a result of evolutionary pressures that shaped human preferences for attractive traits.

💡Sexual Selection

Sexual selection is a mechanism of evolution proposed by Charles Darwin, which explains how certain traits evolve because they increase an individual's chances of attracting mates. The video discusses this concept in the context of beauty, citing the peacock’s tail as an example. The extravagant tail is not beneficial for survival but helps the peacock attract mates, similar to how masculine features influenced by testosterone can signal fitness.

💡Testosterone and Estrogen

Testosterone and estrogen are hormones that influence masculine and feminine facial features, respectively. In the video, testosterone is linked to traits such as square jaws and heavy brows, which are considered attractive in men. Estrogen contributes to features like full lips and high cheekbones, which signal fertility and are found attractive in women. These hormones shape physical attractiveness based on reproductive potential.

💡Beauty Stereotypes

Beauty stereotypes refer to societal biases that associate physical attractiveness with positive qualities, such as intelligence, trustworthiness, and kindness. The video discusses how attractive people are often perceived more favorably and receive advantages, while those with facial anomalies face negative biases. These stereotypes are rooted in deep-seated, often unconscious associations between beauty and goodness, as shown by brain studies.

💡Handicap Principle

The handicap principle is an evolutionary theory that suggests individuals with certain costly traits (like the peacock’s tail or testosterone-influenced male features) demonstrate their fitness by maintaining these traits despite the associated costs. In the video, this principle explains why masculine features, which are linked to suppressed immune function due to high testosterone, might still signal genetic fitness to potential mates.

💡Fusiform Gyrus

The fusiform gyrus is a region of the brain involved in facial recognition. In the video, this area is activated when people view attractive faces, highlighting how the brain processes beauty at a neural level. The fusiform gyrus plays a key role in linking the visual perception of faces with the pleasure centers in the brain, demonstrating the automatic response humans have to beauty.

💡Cultural and Evolutionary Drift

Cultural and evolutionary drift refers to the changes in beauty standards over time due to shifting environmental and social conditions. The video explains that as modern technology and medicine reduce certain survival pressures, like the need to avoid parasites, the universal traits of beauty may evolve. This concept underscores the idea that beauty is fluid and shaped by both biological and cultural forces.

Highlights

Sir Francis Galton introduces a technique to create composite portraits in 1878.

Galton's composite of violent criminals unexpectedly results in a beautiful face.

The concept of beauty is explored through evolutionary psychology and neuroscience.

Average or composite faces are considered more attractive, suggesting genetic diversity.

Symmetry in faces is linked to attractiveness and health.

Maksymilian Faktorowicz's beauty micrometer measures facial asymmetry for beauty enhancement.

Hormones like estrogen and testosterone influence facial features associated with attractiveness.

The irony that testosterone, which can suppress immunity, is linked to attractive masculine features.

The handicap principle explains the evolution of extravagant features like the peacock's tail.

Preferences for beauty can become universal in a group due to reproductive advantages.

Brain areas like the fusiform gyrus and the lateral occipital complex are activated by attractive faces.

Attractive faces automatically trigger neural activity in the visual cortex, even when not consciously perceived.

The 'beauty is good' stereotype is embedded in the brain, influencing social perceptions.

Attractive people often receive unjustified advantages in society based on their looks.

Facial disfigurement is often unfairly associated with negative stereotypes.

The universal attributes of beauty are changing with modern medicine and technology.

The criteria for reproductive success are evolving, leading to a more variable concept of beauty.

Transcripts

It's 1878.

Sir Francis Galton gives a remarkable talk.

He's speaking to the anthropologic institute of Great Britain and Ireland.

Known for his pioneering work in human intelligence,

Galton is a brilliant polymath.

He's an explorer,

an anthropologist,

a sociologist,

a psychologist

and a statistician.

He's also a eugenist.

In this talk,

he presents a new technique by which he can combine photographs

and produce composite portraits.

This technique could be used to characterize different types of people.

Galton thinks that if he combines photographs of violent criminals,

he will discover the face of criminality.

But to his surprise,

the composite portrait that he produces

is beautiful.

Galton's surprising finding raises deep questions:

What is beauty?

Why do certain configurations of line and color and form excite us so?

For most of human history,

these questions have been approached using logic and speculation.

But in the last few decades,

scientists have addressed the question of beauty

using ideas from evolutionary psychology and tools of neuroscience.

We're beginning to glimpse the why and the how of beauty,

at least in terms of what it means for the human face and form.

And in the process,

we're stumbling upon some surprises.

When it comes to seeing beauty in each other,

while this decision is certainly subjective for the individual,

it's sculpted by factors that contribute to the survival of the group.

Many experiments have shown

that a few basic parameters contribute to what makes a face attractive.

These include averaging, symmetry and the effects of hormones.

Let's take each one of these in turn.

Galton's finding

that composite or average faces are typically more attractive

than each individual face that contributes to the average

has been replicated many times.

This laboratory finding fits with many people's intuitions.

Average faces represent the central tendencies of a group.

People with mixed features represent different populations,

and presumably harbor greater genetic diversity

and adaptability to the environment.

Many people find mixed-race individuals attractive

and inbred families less so.

The second factor that contributes to beauty is symmetry.

People generally find symmetric faces more attractive than asymmetric ones.

Developmental abnormalities are often associated with asymmetries.

And in plants, animals and humans,

asymmetries often arise from parasitic infections.

Symmetry, it turns out,

is also an indicator of health.

In the 1930s,

a man named Maksymilian Faktorowicz

recognized the importance of symmetry for beauty

when he designed the beauty micrometer.

With this device,

he could measure minor asymmetric flaws

which he could then make up for with products he sold from his company,

named brilliantly after himself, Max Factor,

which, as you know, is one of the world's most famous brands

for "make up."

The third factor that contributes to facial attractiveness

is the effect of hormones.

And here, I need to apologize for confining my comments

to heterosexual norms.

But estrogen and testosterone play important roles

in shaping features that we find attractive.

Estrogen produces features that signal fertility.

Men typically find women attractive

who have elements of both youth and maturity.

A face that's too baby-like might mean that the girl is not yet fertile,

so men find women attractive

who have large eyes, full lips and narrow chins

as indicators of youth,

and high cheekbones as an indicator of maturity.

Testosterone produces features that we regard as typically masculine.

These include heavier brows,

thinner cheeks

and bigger, squared-off jaws.

But here's a fascinating irony.

In many species,

if anything,

testosterone suppresses the immune system.

So the idea that testosterone-infused features are a fitness indicator

doesn't really make a whole lot of sense.

Here, the logic is turned on its head.

Instead of a fitness indicator,

scientists invoke a handicap principle.

The most commonly cited example of a handicap

is the peacock's tail.

This beautiful but cumbersome tail doesn't exactly help the peacock

avoid predators

and approach peahens.

Why should such an extravagant appendage evolve?

Even Charles Darwin,

in an 1860 letter to Asa Gray wrote

that the sight of the peacock's tail made him physically ill.

He couldn't explain it with his theory of natural selection,

and out of this frustration,

he developed the theory of sexual selection.

On this account,

the display of the peacock's tail is about sexual enticement,

and this enticement means it's more likely the peacock will mate

and have offspring.

Now, the modern twist on this display argument

is that the peacock is also advertising its health to the peahen.

Only especially fit organisms can afford to divert resources

to maintaining such an extravagant appendage.

Only especially fit men can afford the price that testosterone levies

on their immune system.

And by analogy, think of the fact

that only very rich men can afford to pay more than $10,000 for a watch

as a display of their financial fitness.

Now, many people hear these kinds of evolutionary claims

and think they mean that we somehow are unconsciously seeking mates

who are healthy.

And I think this idea is probably not right.

Teenagers and young adults are not exactly known for making decisions

that are predicated on health concerns.

But they don't have to be,

and let me explain why.

Imagine a population

in which people have three different kinds of preferences:

for green, for orange and for red.

From their point of view,

these preferences have nothing to do with health;

they just like what they like.

But if it were also the case that these preferences are associated

with the different likelihood of producing offspring --

let's say in a ratio of 3:2:1 --

then in the first generation,

there would be 3 greens to 2 oranges to 1 red,

and in each subsequent generation,

the proportion of greens increase,

so that in 10 generations,

98 percent of this population has a green preference.

Now, a scientist coming in and sampling this population

discovers that green preferences are universal.

So the point about this little abstract example

is that while preferences for specific physical features

can be arbitrary for the individual,

if those features are heritable

and they are associated with a reproductive advantage,

over time,

they become universal for the group.

So what happens in the brain when we see beautiful people?

Attractive faces activate parts of our visual cortex

in the back of the brain,

an area called the fusiform gyrus,

that is especially tuned to processing faces,

and an adjacent area called the lateral occipital complex,

that is especially attuned to processing objects.

In addition,

attractive faces activate parts of our reward and pleasure centers

in the front and deep in the brain,

and these include areas that have complicated names,

like the ventral striatum,

the orbitofrontal cortex

and the ventromedial prefrontal cortex.

Our visual brain that is tuned to processing faces

interacts with our pleasure centers

to underpin the experience of beauty.

Amazingly, while we all engage with beauty,

without our knowledge,

beauty also engages us.

Our brains respond to attractive faces

even when we're not thinking about beauty.

We conducted an experiment in which people saw a series of faces,

and in one condition,

they had to decide if a pair of faces were the same or a different person.

Even in this condition,

attractive faces drove neural activity robustly in their visual cortex,

despite the fact that they were thinking about a person's identity

and not their beauty.

Another group similarly found automatic responses to beauty

within our pleasure centers.

Taken together, these studies suggest

that our brain automatically responds to beauty

by linking vision and pleasure.

These beauty detectors, it seems,

ping every time we see beauty,

regardless of whatever else we might be thinking.

We also have a "beauty is good" stereotype embedded in the brain.

Within the orbitofrontal cortex,

there's overlapping neural activity

in response to beauty and to goodness,

and this happens even when people aren't explicitly thinking

about beauty or goodness.

Our brains seem to reflexively associate beauty and good.

And this reflexive association may be the biologic trigger

for the many social effects of beauty.

Attractive people receive all kinds of advantages in life.

They're regarded as more intelligent,

more trustworthy,

they're given higher pay and lesser punishments,

even when such judgments are not warranted.

These kinds of observations reveal beauty's ugly side.

In my lab, we recently found

that people with minor facial anomalies and disfigurements

are regarded as less good, less kind,

less intelligent, less competent and less hardworking.

Unfortunately, we also have a "disfigured is bad" stereotype.

This stereotype is probably exploited and magnified

by images in popular media,

in which facial disfigurement is often used as a shorthand

to depict someone of villainous character.

We need to understand these kinds of implicit biases

if we are to overcome them

and aim for a society in which we treat people fairly,

based on their behavior and not on the happenstance of their looks.

Let me leave you with one final thought.

Beauty is a work in progress.

The so-called universal attributes of beauty

were selected for during the almost two million years of the Pleistocene.

Life was nasty, brutish and a very long time ago.

The selection criteria for reproductive success from that time

doesn't really apply today.

For example,

death by parasite is not one of the top ways that people die,

at least not in the technologically developed world.

From antibiotics to surgery,

birth control to in vitro fertilization,

the filters for reproductive success are being relaxed.

And under these relaxed conditions,

preference and trait combinations are free to drift

and become more variable.

Even as we are profoundly affecting our environment,

modern medicine and technological innovation

is profoundly affecting

the very essence of what it means to look beautiful.

The universal nature of beauty is changing

even as we're changing the universe.

Thank you.

(Applause)