The present study examined the impact of different attributes of social stimuli using the stimulus attributes aspect of the Comprehensive Process Model of Engagement (Cohen-Mansfield et al., (2009a)Am J Geriatr Psychiatry. 17:299–307). Participants were 193 residents of 7 Maryland nursing homes with a diagnosis of dementia. Stimuli were chosen to represent different levels of the following social attributes: social versus not social, realistic versus not realistic, animated versus nonanimated, human versus nonhuman, and alive versus not alive. Participants had significantly longer engagement, were significantly more attentive, and displayed a significantly more positive attitude with social stimuli than with nonsocial stimuli. Longer durations and higher ratings of attention and attitude were seen with realistic and animated stimuli as compared to their counterparts. Human and live stimuli resulted in significantly more engagement than their counterparts. Giving any social stimulus to the residents is preferable to providing none, and the social attributes of stimuli should be maximized.