Theory suggests that individuals with avoidant personality disorder (APD) may have experienced rejection or isolation during childhood, that they may be temperamentally hypersensitive, and that they may hold pessimistic expectancies. In a sample of 127 undergraduates, negative childhood memories, sensory-processing sensitivity, and pessimism were assessed. To measure childhood memories, participants wrote open-ended narratives that were evaluated for valence by independent raters. To measure APD features, participants rated the degree of which verbatim DSM-IV criteria were descriptive of themselves. Negative childhood accounts, self-reports of sensory-processing sensitivity, and pessimism were correlated with DSM-IV APD features, even after controlling for the influence of present negative mood. Interactions suggested that pessimism was more strongly related to APD features among participants who were either highly sensitive or recalled adverse childhood experiences (e.g., isolation, rejection, conflict). Implications for theory and intervention are discussed.