This study set out to examine parents’ and teachers’ explanations of the malleability of children’s competences. Parents and teachers were asked in which aspect of schoolwork the child could improve his/her competence most and to explain why. The participants were parents and teachers of third- and sixth-grade boys and girls (n=97). The parents and teachers were found to refer to the amount of effort, motivation, and ability in their explanations of the malleability of children’s competences. The explanations concerning ability divided into those in which the child was seen as possessing ability and those in which the child was seen as lacking ability or having difficulties that prevented her/him from succeeding. The teachers perceived sixth-graders as needing more effort and motivation than third-graders did, and girls as somewhat more competent and motivated than boys. The teachers also seemed to explain children’s potential for improvement in more complex ways than the parents did.