The study included 48 participants who were paired up with a partner who could administer to them either an audible tone or an electric shock. In the intentional condition, participants were shocked when their partner chose the shock option.
In the unintentional condition, participants were shocked when their partner chose the tone option.
Thus, in this condition, they only received a shock when their partner did not intend them to receive one. The computer display ensured that participants both knew their partner's choice and that a shock would be coming, to ensure the shock was not more surprising in the unintentional condition.
Despite identical shock voltage between conditions, those in the intentional condition rated the shocks as significantly more painful. Furthermore, those in the unintentional condition habituated to the pain, rating them as decreasingly painful, while those in the intentional condition continued to feel the full sting of pain.
Source-ANI
TAN/M