Child who has no siblings.

The sequence in which children are born into the family.

Organized efforts by communities or organizations to improve the health and well-being of the child.

Children with mental or physical disabilities that interfere with usual activities of daily living and that may require accommodation or intervention.

Any observable response or action of a child from 24 months through 12 years of age. For neonates or children younger than 24 months, INFANT BEHAVIOR is available.