Table 1.

Descriptive Statistics for all Study Variables

Variable	N	Mean	SD	Correlation with Retention	Effect Size	Odds-Ratioa,b
Retained (yes – no)	769	21.5	41.1	n/a	n/a
Academic competencies:
Woodcock-Johnson:
Reading W	752	434.0	26.5	−0.273**	−0.52	1.032**
Math W	752	462.9	13.3	−0.131**	−0.28	1.021**
Teacher-rated achievement	669	4.02	1.42	−0.195**	−0.38	1.400**
Teacher-rated engagement	672	3.53	1.26	−0.145**	−0.29	1.460**
Unit IQ	775	92.8	14.7	−0.107**	−0.24	1.091**
Sociodemographic
characteristics:
% femalec	784	52.6	50.0	0.048	0.12	1.264
Economic disadvantagec	750	61.3	48.7	0.101**	0.27	1.697**
Age in months	783	6.57	0.39	−0.150**	−0.32	2.959**
Social, emotional and
behavioral characteristics:
Ego resilience	673	3.51	0.81	−0.123*	−0.25	1.383**
Aggression	426	−0.014	0.85	0.025	0.05	1.073
Hyperactivity	426	0.002	0.87	0.114**	0.23	1.354**
Emotional problems	423	−0.013	0.78	0.045	0.09	1.140
Prosocial behavior	446	−0.048	0.81	−0.070	−0.12	1.236
School context:
Teacher-rated support	670	3.75	0.77	−0.074*	−0.16	1.256*
Teacher-rated conflict	674	1.87	1.01	0.057	0.14	1.086
School % economic disadvantage	737	0.57	0.29	0.089*	0.22	1.009*
Home Environment:
Parent-school:
Communication	497	2.65	0.67	0.108*	0.24	1.485*
Involvement	499	2.26	0.53	0.039	0.08	1.189
Shared responsibility	498	4.37	0.48	−0.074	−0.14	1.264
Positive perception	499	4.21	0.75	0.113*	0.27	1.475*
Aspirations	581	7.65	2.01	−0.106*	−0.20	1.131*
Mobilityc	769	16.1	34.9	0.137**	0.39	2.212**

^*p < .05

^**p < .01

^aOdds-ratio equals probability of being retained over probability of being promoted per unit change for the correlated variable.

^bSignificance for chi square statistic associated with logistic regression with df = 1.

^ccontingency coefficient for binary variables denoted as % for Pearson association estimate of correlation, for logistic regression a binary predictor.