Table 5.

Least square means (standard error) representing the interaction of only-child effects by OCP.

	Only Children		Not Only Children
	Pre-OCP	Post-OCP	Pre-OCP	Post-OCP
	n = 194	n = 361	n = 241	n = 137
Positive Attributes By Judge
Self	23.6 (0.54)	24.6 (0.49)	24.8 (0.52)	24.2 (0.53)
Parent	20.8 (0.57)	23.5 (0.41)	22.4 (0.54)	23.6 (0.55)

Note. Linear regression models controlled for children's age, mother's age, father's age, parent's educational attainment, family income, and region with data clustered by school. Planned comparisons indicated that among children born before the OCP, only children had lower self-evaluations than did children with siblings. For parent evaluations, planned comparisons indicated that only children born after the OCP had more positive scores than only children born before the OCP. Similarly, only children born after the OCP had significantly more positive parent scores than their peers with siblings regardless of whether they were born before or after the OCP.