The consistency with which people interpret relationship-based information has important implications for attachment theory and research. Our objective is to determine whether there are attachment-related individual differences in the manner and the consistency with which individuals interpret hypothetical relationship behaviors. In two studies (N = 629, 79% female, 63% American, Mage = 29; N = 820, 78% female, 65% American, Mage = 29), we assessed participants' ability and consistency in relationship behavior interpretation across two blocks and estimated how they would have performed had they interpreted information perfectly consistently. Secure participants were generally more consistent in their interpretations relative to insecure participants. Estimates of perfectly consistent interpretation revealed that improvements to both systematic factors related to behavior interpretation (e.g., working models) and consistency would have led to a more secure interpretation style for participants of all attachment styles. Results imply that both secure and insecure individuals process relationship-based information according to secure scripts, but insecure individuals do so inconsistently. Our results imply that, due to the inconsistent behavioral responses that may occur as a result of inconsistent information processing, the consistency with which people process relationship-related information will be related to relationship satisfaction. Further directions for future research are discussed.