Shy people are characterized as engaging in self-derogatory thinking leading to anxiousness and inhibition, while people who are publicly self-conscious are focused on the impression they create on others. In addition, public self-consciousness has been described as an antecedent of shyness. In the present research, we tested additive versus interactive hypotheses about the association of shyness and public self-consciousness with dysfunctional social interaction. Undergraduate men varying in shyness and public self-consciousness engaged in a conversation with an unfamiliar woman confederate. Following the conversation, subjects completed self-report measures focusing on their responses during the conversation. Only main effects for shyness and public self-consciousness were found, supporting an additive hypothesis. Shyness was related to all dependent variables reflecting a negative self-bias, while public self-consciousness was not. In particular, shyness was inversely related to the balance of subjects' positive and negative thoughts and to reported use of protective as well as avoidance of acquisitive self-representation responses. Public self-consciousness was positively related to use of protective self-presentation responses but unrelated to acquisitive responses.