The occurrences of pervasive developmental disabilities and a four-year-old boy’s fighting behavior over toys with his sibling were reduced by showing him video teaching materials intended to promote the verbalization of emotions and the acquisition of other people’s perspectives. The video teaching materials depicted a scene of the subject playing with his sibling. In the video, the subject says, “wait,” when his sibling tries to take away a toy he is playing with. We also inserted other lines into the narration, such as,“ when not using the toy, lending it to your sibling will make him or her happy.” During the intervention period after watching the video, the frequency of occurrences of fights over toys stabilized compared to that of the baseline period. However, the frequency of occurrences did not decrease, nor could we confirm the retention of the intervention effects. We did observe scenes in which the subject repeated lines from the video’s narration; however, due to instances such as one in which the sibling took away the toy even though the subject said, “wait,” we inferred that the subject was unable to accumulate enough successful experiences to retain the intervention effects.