Zajonc observed two categories of behaviours—dominant responses to tasks that are easier to learn and which dominate other potential responses and nondominant responses to tasks that are less likely to be performed. In his Theory of Social Facilitation, Zajonc concluded that in the presence of others, when action is required, depending on the task requirement, either social facilitation or social interference will impact the outcome of the task. If social facilitation occurs, the task will have required a dominant response from the individual resulting in better performance in the presence of others, whereas if social interference occurs the task will have elicited a nondominant response from the individual resulting in subpar performance of the task.