Birth order can affect an individual's personality development.
Older siblings exhibit personality traits that differ from their younger siblings.
Falbo found that self-esteem was higher among firstborn children than later born children. He also found that firstborn children tend to be more competitive than their younger siblings. An individual's relation to his siblings may affect his self-image. Gates et al. used three different scales, including one designed to measure the level of self-concept. The children questioned ranged in age from 7 to 12 and were selected from public and private schools.