Ironic process theory (IPT), also known as the Pink elephant paradox [1] suggests that when an individual intentionally tries to avoid thinking a certain thought or feeling a certain emotion, a paradoxical effect is produced: the attempted avoidance not only fails in its object but in fact causes the thought or emotion to occur more frequently and more intensely.[2] IPT is also known as "ironic rebound," or "the white bear problem."[3]
The phenomenon was identified through thought suppression studies in experimental psychology. Social psychologist Daniel Wegner first studied ironic process theory in a laboratory setting in 1987.[4] Ironic mental processes have been shown in a variety of situations, where they are usually created by or worsened by stress. In extreme cases, ironic mental processes result in intrusive thoughts about doing something immoral or out of character, which can be troubling to the individual. These findings have since guided clinical practice. For example, they show why it would be unproductive to try to suppress anxiety-producing or depressing thoughts.[5]