The term stress was first acclimated by the endocrinologist Hans Selye in the 1930s to identify physiological responses in laboratory animals. He later broadened and popularized the intellection to include the perceptions and responses of humans trying to adapt to the challenges of everyday life. Stress, in Selye's terminology, refers to the reaction of the organism, and stressor to the Stress Balls perceived threat.

There was renewed laboratory research into the neuroendocrine, molecular and immunological bases of stress, conceived as a useful heuristic not necessarily tied to Selye's original hypotheses. Stress management techniques were developed.