Their languages and the specific attributes of their environment differ drastically: one culture may be oriented around a river, another around the migration of a particular animal. But many decades of research have unearthed what anthropologist Bruce Trigger calls “cross-cultural uniformities in human behavior.” The uniformities tend to exist under the surface, leading to underlying patterns of thought that are remarkably similar across cultures, even while their manifestations in each culture's beliefs and practices are profusely variable.