Selective effects of explanation on learning during early childhood.

•Children (3–6-years) participated in a problem-solving task involving a gear machine.•In Study 1, learning following self-explanation was compared to a non-verbal task.•In Study 2, learning following self-explanation was compared to verbal description.•Explanation selectively supports learning causal mechanisms and generalization.•Explanation does not improve memory for causally irrelevant, perceptual details.