Testosterone shifts the balance between sensitivity for punishment and reward in healthy young women.

Animal research has demonstrated reductions in punishment sensitivity and enhanced reward dependency after testosterone administration. In humans, elevated levels of testosterone have been associated with violent and antisocial behavior. Interestingly, extreme forms of violent and antisocial behavior can be observed in the psychopath. Moreover, it has been argued that reduced punishment sensitivity and heightened reward dependency are crucially involved in the etiology and maintenance of psychopathy. A task that has been proven to be capable of simulating punishment-reward contingencies is the IOWA gambling task. Decisions to choose from decks of cards become motivated by punishment and reward schedules inherent in the task. Importantly, clinical and subclinical psychopaths demonstrate a risky, disadvantageous pattern of decision-making in the task, indicating motivational imbalance (insensitivity for punishment and enhanced reward dependency). Here, in a double-blind placebo-controlled crossover design (n = 12), whether a single administration of testosterone would shift the motivational balance between the sensitivity for punishment and reward towards this tendency to choose disadvantageously was investigated. As hypothesized, subjects showed a more disadvantageous pattern of decision-making after testosterone compared to placebo administration. These findings not only provide the first direct evidence for the effects of testosterone on punishment-reward contingencies in humans, but they also give further insights into the hypothetical link between testosterone and psychopathy.