Robert M. Yerkes

Robert M. Yerkes was an American psychologist best known for his research on animal behavior and intelligence. He developed experiments, including the use of intelligence tests, to study mental capabilities in animals like monkeys. Yerkes also contributed to understanding the relationship between arousal and performance, formulating the Yerkes-Dodson Law, which suggests that there’s an optimal level of alertness for best performance—too little or too much arousal can hinder functioning. His work helped shape psychological testing methods and our understanding of how biological states influence behavior and cognition.