Hamermesh’s work fleshes out something old and intuitive: Making decisions is hard, and we often rely on our first impressions. Some people look trust-worthy, and some people look like crooks. Some people look like they can be president, and some people are Dennis Kucinich. Cute students are rated as smarter than uglier students, older-looking people seem more mature, and taller people seem more authoritative. The economics benefits of height (particularly for men) are so widely established that the Harvard economist Greg Mankiw once cheekily suggested a Tallness Tax to level the playing field.

First impressions are short-cuts, but sometimes our instincts are off. In one study of hedge funds, Ankur Pareek and Roy Zuckerman found that managers that looked more trustworthy attracted more funds, but there was “no evidence that perceived trustworthiness predicts actual manager skill.” In fact, the trusty-seeming managers generated worse returns. The same principle appears in the peer-to-peer lending market, where Enrichetta Ravina found that pretty women, in particular, get cheaper loans, despite being more likely to default.