Not long ago, most people would probably judge how trustworthy you were based entirely on your physical appearance. More specifically, the pseudoscience of physiognomy claimed that a person's facial expressions could tell you a lot about their personality: were they honest, would you get along with them, are they good at their job, etc. Today, we know that kind of thinking is a dangerous pseudoscience. We also know that looks do play a big role in how we evaluate people, and that these evaluations are often based on cultural stereotypes. Psychology professor Alexander Todorov explains how our biases affect the way we treat people, and by extension, how we think of ourselves in relation to them. ALEXANDER TODOROV: So physiognomy, or the so-called pseudoscience of reading character from faces, has a very, very long history. The first historical document dates all the way back to the time of Aristotle, but it really got extremely, extremely popular in the 18th and 19th century.