Therefore, this study will test the following three hypotheses about the impact of sibling status on interpersonal orientation. These hypotheses represent the preponderance of previous research or, where lacking, popular thinking:
Only and first horns will have higher self-esteem than later horns.
Only and first borns will have a more internal locus of control than later.borns.
Only children will be lonelier and more self-centered than people who grew up with siblings.