Nervousness may be due to physical or psychological conditions. It may appear at any age. Its causes may be immediate or may lie farther back in childhood, infancy, or heredity. As the nervous system was the latest to evolve, it is therefore the least stable, and the most likely to suffer under stress of conditions. If there is a heredity in either branch of the family, either of marked nervous defect, alcoholism, or neurasthenia, special precautions should from the first be taken to overcome this predisposition in the child.
Other causes of nervousness in children include:
Irregularity of régime
Poor nutrition
Constipation
Insufficient sleep, fatigue
Indoor life
Decaying teeth
Adenoids or enlarged tonsils
Eyestrain