Paul Rozin, PhD, explores the “holes” in psychology—those topics that most psychologists overlook.

In his 2007 Distinguished Scientific Contributions Award address, Rozin, a professor at the University of Pennsylvania who specializes in cultural psychology, identified some of the voids he believes would benefit from more research:

•  Positive versus negative events. Psychologists are much more likely to study negative events, such as depression and anger, than positive feelings, such as joy and pleasure. “We don’t even know why hobbies and passions develop.”

•  Food and eating. Eating has become a socially elevated event—no longer just a means of sustenance—which is why it’s such an interesting area of study. “Humans have changed it so much, and if you want to understand culture, you certainly don’t want to overlook that,” said Rozin. Yet psychologists know little about the origin of food preferences.

•  Cultural environment. Most psychological studies still use American college students as participants, even though this population represents a tiny proportion of the world’s cultural richness. Studies also often do not take into account the societal factors that shape behavior and preferences. Americans, for example, attach great significance to choice, but people in traditional societies such as India may be more influenced by custom.

—L. Meyers