A common problem afflicting modern psychology is that it’s mainly based on experiments with middle-class white people, often from North America or Europe. Open up the field of inquiry to other cultures, social circles or ethnic groups and different trends come to the fore.

Take the effects of a baby-face. Decades of studies have found that rounded, smooth, young-looking faces engender trust and sympathy. People adorned with such youthful looks tend to be treated with more sensitivity and patience, receive more lenient sentences, and make better spokespeople during PR crises. But these disarming faces come at a price – they’re also associated with weakness and incompetence, which can harm those striving for positions of authority. Indeed, previous studies have