Within any age group, of course, there is likely to be considerable variation. Some of this variation appears to be genetically based. For example, boys of all ages are generally more active than girls. Environmental influences also play a part. For example, it has been observed that some very active children become even more restless whenever adults try to restrict their activity level.
Boys tend to be more active than girls.
During the preschool years, there are wide variations in what is considered a normal level of activity. Trying to force a restless child to sit still will generally not be effective in settling him down. Being sensitive to your child's unique characteristics and making reasonable accommodations to fit his own level of activity will generally be in his best interest. In the meantime, being patient with your child's activity level is most important during the preschool years, even though at times it may be a great frustration to you. In their most formative early years, children learn right from wrong primarily by observing their parents.