'Phrenology' has an old-fashioned ring to it. It sounds like it belongs in a history book, filed somewhere between bloodletting and velocipedes. We'd like to think that judging people's worth based on the size and shape of their skull is a practice that's well behind us. However, phrenology is once again rearing its lumpy head. In recent years, machine-learning algorithms have promised governments and private companies the power to glean all sorts of information from people's appearance.

Franz Joseph Gall gained fame and notoriety in the 1800s for his theories about the mind. Gall believed that the shapes and bumps of the skull provided a lot of information about a person. These theories, phrenology, attributed skull shapes and bumps to personality, traits and morality. In the 1830s and 1840s, phrenology gained popularity in the USA. Based on skull measurements, physician Charles Caldwell claimed Africans were mentally inferior.

While there was some renewed interest in the theory in the 20th century due to the rise of disciplines like evolution, criminology, and anthropology, it soon was almost completely abandoned. This year, however, in the spirit of scientific fun, my colleagues decided to put this old theory to the test. They did so by repurposing various pieces of sophisticated software, originally designed for MRI brain analysis. Where normally these tools carefully discard all bits of skull, allowing analysis of the brain alone, they engineered them to do the reverse: relegating all of the brain to the trash, instead keeping the bony bits for analysis. From this surface structure, they could create a detailed map of the contours--bumps--of individual skulls.

The stunning advancement of artificial intelligence and machine learning has brought advances in society. These technologies have improved medicine and how quickly doctors can diagnose disease, for example. IBM's AI platform Watson helps reduce water waste in drought stricken areas. AI even entertains us--the more you use Netflix, the more it learns what your viewing preferences are and makes suggestions based on what you like to watch. However, there is a very dark side to AI, and it's worrying many social scientists and some in the tech industry.

The fields of artificial intelligence and machine learning are moving so quickly that any notion of ethics is lagging decades behind, or left to works of science fiction. This might explain a new study out of Shanghai Jiao Tong University, which says computers can tell whether you will be a criminal based on nothing more than your facial features. The bankrupt attempt to infer moral qualities from physiology was a popular pursuit for millennia, particularly among those who wanted to justify the supremacy of one racial group over another. But phrenology, which involved studying the cranium to determine someone's character and intelligence, was debunked around the time of the Industrial Revolution, and few outside of the pseudo-scientific fringe would still claim that the shape of your mouth or size of your eyelids might predict whether you'll become a rapist or thief. Not so in the modern age of Artificial Intelligence, apparently: In a paper titled "Automated Inference on Criminality using Face Images," two Shanghai Jiao Tong University researchers say they fed "facial images of 1,856 real persons" into computers and found "some discriminating structural features for predicting criminality, such as lip curvature, eye inner corner distance, and the so-called nose-mouth angle."

The fields of artificial intelligence and machine learning are moving so quickly that any notion of ethics is lagging decades behind, or left to works of science fiction. This might explain a new study out of Shanghai Jiao Tong University, which says computers can tell whether you will be a criminal based on nothing more than your facial features. The bankrupt attempt to infer moral qualities from physiology was a popular pursuit for millennia, particularly among those who wanted to justify the supremacy of one racial group over another. But phrenology, which involved studying the cranium to determine someone's character and intelligence, was debunked around the time of the Industrial Revolution, and few outside of the pseudo-scientific fringe would still claim that the shape of your mouth or size of your eyelids might predict whether you'll become a rapist or thief. Not so in the modern age of Artificial Intelligence, apparently: In a paper titled "Automated Inference on Criminality using Face Images," two Shanghai Jiao Tong University researchers say they fed "facial images of 1,856 real persons" into computers and found "some discriminating structural features for predicting criminality, such as lip curvature, eye inner corner distance, and the so-called nose-mouth angle."