["Japanese Psychological Research, EarlyView. ", "\nAbstract\nAddressing psychological stress in parenting is essential for preventing the intergenerational transmission of childhood maltreatment (CM). While social support can alleviate parenting stress, it may be less effective for parents with higher CM levels, highlighting the need to explore additional moderating factors. Self‐insight is a potential internal resource that may directly reduce stress and enhance the benefits of social support. Using cross‐sectional data from 1,889 Japanese mothers, this study tested a model examining these mechanisms. Results indicated that higher self‐insight was generally associated with lower psychological stress. However, higher self‐insight was associated with a stronger negative relationship between CM and perceived social support. Although self‐insight was related to greater perceived social support, it also weakened the stress‐buffering effect of social support. These findings suggest that while self‐insight generally promotes psychological adaptation, it may also intensify the negative association between CM and perceived social support and attenuate the stress‐buffering role of social support across all CM levels. Interventions should therefore consider how these factors interact in complex and sometimes paradoxical ways depending on individual cognitive tendencies.\n"]