Sex differences in the activity level of preschool children as a possible precursor of hyperactivity.

The major objective of the present study was to determine whether or not preschool age boys had a higher activity level than girls. While it is a widely known fact that more boys than girls are referred to specialists for being hyperactive, the question of whether a sex-linked pattern of hyperactivity is observable in the general population remains unanswered. To investigate this issue, the activity levels of preschool children from a "normal" sample were measured randomly by an observation technique as they took part in a nursery school program. The results not only indicated that boys were more active than girls, but that the boy's behavioral activity was manifested in patterns that were similar in nature to those often included as part of the various definitions of hyperactivity. The implication of the results were discussed, and future research needs were delineated.