Physiognomy is the old idea that you can tell a person's character or future just by looking at their face, but it is not a real science.

Key idea: Physiognomy has roots in ancient cultures, with philosophers like Aristotle exploring the idea of linking appearance to character.

The idea of connecting how someone looks to their inner self goes way back to ancient times. In ancient India, there was something called Samudrika Shastra, which linked body features to personal traits. In ancient China, face reading, or mianxiang, was practiced at least as far back as the Spring and Autumn period.

In ancient Greece, around 500 BC, people started writing about physiognomy. The famous philosopher Aristotle often talked about how appearance might relate to character. He wondered if changes in the body and soul were connected naturally. For example, if someone had a certain look, could it mean they had certain feelings or desires?

One of the first detailed books on physiognomy, called "Physiognomonica," is thought to come from Aristotle's school. It looked at how different races and even animals behaved to draw conclusions about human character. Another story tells of the ancient Greek mathematician Pythagoras, who supposedly turned away a student because his face suggested bad character. However, when a physiognomist looked at Socrates and said he was prone to bad temper, Socrates agreed, saying he had to work hard to control those natural urges.

Key idea: Physiognomy was widely accepted in the Middle Ages but started to lose favor by the Renaissance, with some thinkers calling it unscientific.

During the Middle Ages and the Renaissance, physiognomy was still a popular idea. In the 12th century, a Persian philosopher named Fakhr al-Din al-Razi wrote about how physical features might connect to moral qualities.

The word "physiognomy" was common in English then, sometimes spelled "fisnamy." English universities even taught it until King Henry VIII outlawed it in the 1500s, grouping it with "subtle, crafty and unlawful games" like palm reading. Around this time, scholars started to dislike the whole concept.

Even Leonardo da Vinci in the early 1500s called physiognomy "false" and said it had "no scientific foundation." However, he did believe that lines on a person's face, caused by expressions, could show personality. For example, he thought deep lines between the eyebrows meant someone was easily angered.

“Leonardo da Vinci dismissed physiognomy in the early 16th century as "false," a chimera with "no scientific foundation."”

Key idea: Physiognomy saw a revival in the 18th and 19th centuries, influencing literature and art, but also leading to harmful stereotypes.

The idea of physiognomy became popular again in modern times, largely thanks to a Swiss pastor named Johann Kaspar Lavater in the late 1700s. His writings on the subject became very well known and were translated into many languages. Some scientists accepted his ideas, but others, like Georg Christoph Lichtenberg, criticized them. Lichtenberg argued that watching someone's behavior was a better way to understand their character than just looking at their face.

Lavater's ideas were also supported by people like Sir Thomas Browne, an English doctor and philosopher. Browne believed that faces held "the motto of our Souls," meaning our inner nature could be read in our features. He even suggested that different regions or countries had distinct facial features that showed their people's nature. Another Italian scholar, Giambattista Della Porta, used pictures of animals to show how human faces might relate to animal characteristics.

The popularity of physiognomy continued to grow through the 18th and 19th centuries. Many authors, like Charles Dickens and Charlotte Brontë, used detailed descriptions of their characters' appearances to hint at their personalities. While this added richness to stories, it also led to more stereotyping based on gender, class, and race.

“Browne in his Religio Medici (1643) discusses the possibility of the discernment of inner qualities from the outer appearance of the face, and wrote: "there is surely a Physiognomy, which those experienced and Master Mendicants observe."”

Key idea: Phrenology and criminology in the 19th century tried to use physical traits to explain personality and criminal behavior, but these ideas were deeply flawed and are now discredited.

Around the same time physiognomy was popular, another similar idea called phrenology emerged. Phrenology claimed you could tell a person's mental traits and personality by feeling the bumps on their skull. While phrenology and physiognomy were different, they were often linked and sometimes even confused with each other.

In the 19th century, some people tried to use physiognomy in criminology, the study of crime. An Italian doctor named Cesare Lombroso believed that criminals were born with certain physical traits, like large jaws or sloping foreheads, that made them more likely to commit crimes. He thought these traits were "throwbacks" to earlier, more primitive humans. Lombroso's ideas were based on flawed science and are now seen as racist and sexist, but he is sometimes called the "father of scientific criminology" because he tried to use scientific methods, even if his conclusions were wrong.

Lombroso's theories had a big impact, suggesting that crime was not a matter of free will but a result of a person's genes. He even expanded his ideas to include different types of "insane criminals." However, modern science has completely rejected his theories due to their biases and lack of evidence.

Key idea: Modern physiognomy appears on social media and in some AI applications, but these uses are often biased, raise ethical concerns, and do not rely solely on facial features.

In the 20th century, a French psychiatrist named Louis Corman developed a concept called morphopsychology. This idea suggested that the way our faces are shaped comes from "vital forces" inside our bodies. It was another attempt to link physical appearance to inner traits.

Today, physiognomy has seen a strange return, especially on social media. People are using memes, face filters, and online discussions to talk about how physical traits might relate to actions or social status. For example, some online communities have spread ideas about skull shape and femininity. This trend worries many because it can make pseudoscientific beliefs seem normal and lead to harmful stereotypes.

Artificial intelligence (AI) is also playing a role. Some AI systems have been developed that claim to predict things like a person's sexual orientation, criminal tendencies, or political views just from their face. Critics argue that these AI systems are often biased because the data they learn from contains existing stereotypes. This raises serious concerns about privacy and how such technology could be misused by governments or companies.

Despite its problematic past, some modern scientific research still looks at the relationship between facial features and character. For instance, there is evidence that a person's character can actually influence their facial appearance over time. Also, how we look affects how others first see us, which can then change how they treat us, and eventually, how we see ourselves and behave. This is called a self-fulfilling prophecy.

Some studies have found small links, like a wider face in ice hockey players being connected to more aggressive penalties. And while AI can predict things like political orientation better than chance, it often uses more than just facial features. It might also pick up on things like makeup, glasses, or even the quality of the image itself, rather than just the underlying face shape. This means the AI is not truly doing physiognomy, but rather picking up on other clues in the image.