To empirically test his drive theory of social facilitation and inhibition, Robert Zajonc conducted a study using cockroaches. He hypothesized that the presence of other cockroaches would improve performance on a simple task but impair performance on a difficult one. Cockroaches were placed in either a simple straight runway or a complex cross-shaped maze, both while alone and in the presence of an audience of other cockroaches. The results showed that cockroaches completed the simple runway faster with an audience, but completed the complex maze slower when watched, confirming Zajonc's hypothesis and providing support for his drive theory.