Table 1.
Descriptive Statistics of Selected Variables (N = 8,920).
| Variable | M or Proportion (SD) |
|---|---|
| Executive Functions | |
| Working memory, spring kindergarten | 15.2 (2.7) |
| Cognitive flexibility, spring kindergarten | 451.2 (30.1) |
| Inhibitory control, spring kindergarten | 5.1 (1.3) |
| Socio-demographic Characteristics | |
| White | 52.1 % |
| Black | 13.4 % |
| Hispanic | 24.3 % |
| Asian | 4.5 % |
| Other race/ethnicity | 5.6 % |
| Female | 48.6 % |
| Lowest SES quintile, kindergarten | 21.0 % |
| Second lowest SES quintile, kindergarten | 24.2 % |
| Middle SES quintile, kindergarten | 23.2 % |
| Second highest SES quintile, kindergarten | 16.5 % |
| Highest SES quintile, kindergarten | 15.1 % |
| Non-English used at home, spring kindergarten | 16.2 % |
| IEP, spring 2nd grade | 11.1 % |
| Age (in months), spring 2nd grade | 97.6 (4.4) |
| Academic Achievement | |
| Reading achievement, spring kindergarten | 0.6 (0.7) |
| Mathematics achievement, spring kindergarten | 0.5 (0.6) |
| Science achievement, spring kindergarten | 0.2 ((0.6) |
| Vocabulary, spring kindergarten | 19.2 (2.1) |
| Reading achievement, spring 2nd grade | 2.1 (0.6) |
| Mathematics achievement, spring 2nd grade | 2.5 (0.8) |
| Science achievement, spring 2nd grade | 1.6 (0.9) |
| Behavioral Functioning | |
| Externalizing problem behavior, spring kindergarten | 1.6 (0.6) |
| Internalizing problem behavior, spring kindergarten | 1.5 (0.5) |
| Behavioral self-regulation, spring kindergarten | 3.1 (0.7) |
| Externalizing problem behavior, spring 2nd grade | 1.7 (0.6) |
| Internalizing problem behavior, spring 2nd grade | 1.6 (0.5) |
| Behavioral self-regulation, spring 2nd grade | 3.1 (0.7) |
Note. N rounded to nearest 10. Continuous variables standardized. Sampling weight used.
IEP = Individualized Educational Plan; SES = socioeconomic status.