Final answer:
Seligman is credited with developing the learned helplessness theory of depression, which suggests that individuals who perceive negative life events as uncontrollable may be more prone to developing depression.
Step-by-step explanation:
Psychologist Martin Seligman is credited with developing the learned helplessness theory of depression. According to this theory, learned helplessness occurs when individuals believe they have no control over negative events in their lives, leading to feelings of helplessness and passivity. Seligman's experiments with dogs in the 1960s demonstrated that animals who experienced uncontrollable shocks without the ability to escape later exhibited learned helplessness. This theory has since been applied to understanding depression in humans, suggesting that individuals who perceive their negative life events as uncontrollable may be more prone to developing depression.