In this three-year longitudinal study, children were asked to choose the "best" strategy for dealing with hypothetical peer provocations and to justify "why" that was their choice at the end of first, second, and third grades. Teachers and parents also rated children's emotional and behavioral problems. Children's justifications were subjected to qualitative analyses to identify distinct content categories. These included getting others into trouble or avoiding it, dichotomous reasoning about good (kind) versus bad (mean) strategies, appeals to authorities for help, situation-specific solutions that anticipated consequences of actions, or general rules or solutions that could or should be used in similar conflicts to effect positive outcomes. These justification categories were related to the children's grade levels. Older children were more likely to use more story-specific justifications and to refer to the perspectives of others and to future consequences in their justification responses. Children who used justifications that involved getting others into trouble or avoiding it had higher levels of teacher ratings of concurrent emotional and behavioral problems at second and third grades and to parent ratings of emotional problems at third grade.