Four studies were conducted to better understand the relationship between arousal, conformity, and the influence of arbitrary and genuine social information. Experiment 1 found that conforming to an apparently genuine majority led to lower levels of autonomic arousal than did independence. Experiment 2 replicated the same findings under nonrealistic conditions in which the experimenter, in front of the participant, told the majority which response to give, thus removing social information from the response. Experiment 3 used arousal-based reasoning to predict that if disagreeing with a majority leads to higher arousal than conformity, even when majority responses contain no social information, participants will conform to majority responses under those same conditions, which was supported. Experiment 4 attempted to broaden our understanding of how arbitrary and real majority responses affect conformity by varying the size of the majority and whether majority responses were arbitrary or genuine. Responses were significantly influenced in all experimental conditions, thus replicating Experiment 3, but more influence occurred with a larger majority that appeared to be giving genuine responses. Our findings expand our understanding of the factors involved in the typical conformity situation by showing that the responses given by the majority affect conformity, whether or not they are genuine, though genuineness adds to the effect with a group size of 3. Also, we argue that taking an arousal-based view provides a way of viewing these results as part of a broader homeostatic behavioral system, although the compatibility of the results with other approaches is acknowledged.