Objective: Early relational trauma has been posited to be responsible for dysfunctional self schema as negative feedback derived from abusive close others may influence the development of self-evaluation. However, the association between early relational trauma and negative self-evaluation has proven inconsistent. In addition to the evaluative aspect, early relational trauma may impact on the procedural aspect of self schema, with a difficulty in differentiating mental representations derived from others from those generated internally by the self. Method: To test this hypothesis, the authors adopted a source attribution paradigm tapping on the distinction between mental representations generated by the self or derived from another person in a nonclinical sample, together with scales measuring self-evaluation and early relational experiences. Results: The results showed that individuals with early relational trauma tended to attribute the representations externally derived as internally generated, although there were no associations between early relational trauma and self-evaluation. Importantly, early relational trauma had unique contribution to source misattribution independent from common covariates including early nonrelational trauma, parental dysfunction, general memory function, and negative affect states. Conclusions: Erroneously identifying information derived from other people as self-generated may be a specific sociocognitive propensity linked to early relational trauma and may impact upon the development of self schema.