Table 1.
Descriptive Statistics of the Study’s Analytical Sample
| Variable | M | SD | Min | Max |
|---|---|---|---|---|
| Gender – male (T1) | 0.50 | 1.00 | 0.00 | |
| Age at K entry in months (T1) | 68.49 | 4.23 | 79.00 | 54.00 |
| Mother’s educational level (T5) | ||||
| Less than high school | 0.11 | 1.00 | 0.00 | |
| High school diploma or equivalent | 0.26 | 1.00 | 0.00 | |
| Some college (including vocational/technical training) | 0.35 | 1.00 | 0.00 | |
| Bachelor’s degree or higher | 0.28 | 1.00 | 0.00 | |
| Father’s educational level (T5) | ||||
| Less than high school | 0.13 | 1.00 | 0.00 | |
| High school diploma or equivalent | 0.28 | 1.00 | 0.00 | |
| Some college (including vocational/technical training) | 0.27 | 1.00 | 0.00 | |
| Bachelor’s degree or higher | 0.31 | 1.00 | 0.00 | |
| Family living below federal poverty level (T5) | 0.18 | 1.00 | 0.00 | |
| Family received AFDC (T5) | 0.03 | 1.00 | 0.00 | |
| Family received food stamps (past 12 months) (T5) | 0.08 | 1.00 | 0.00 | |
| Received WIC (T1) | ||||
| During both pregnancy and childhood | 0.27 | 1.00 | 0.00 | |
| During either pregnancy or childhood | 0.06 | 1.00 | 0.00 | |
| During neither pregnancy nor childhood | 0.66 | 1.00 | 0.00 | |
| Head start participation (T1) | 0.12 | 1.00 | 0.00 | |
| Race (T1) | ||||
| Black non-Hispanic | 0.11 | 1.00 | 0.00 | |
| Hispanic | 0.17 | 1.00 | 0.00 | |
| Asian | 0.06 | 1.00 | 0.00 | |
| Other | 0.05 | 1.00 | 0.00 | |
| White non-Hispanic | 0.61 | 1.00 | 0.00 | |
| Household structure (T5) | ||||
| Single-parent family | 0.19 | 1.00 | 0.00 | |
| Other structure | 0.12 | 1.00 | 0.00 | |
| Two parents, both biological | 0.69 | 1.00 | 0.00 | |
| Number of siblings in household (T5) | 1.57 | 1.17 | 11.00 | 0.00 |
| Primary home language – not English (T4) | 0.11 | 1.00 | 0.00 | |
| Current mom teenager at first birth – younger than 19 (T1) | 0.21 | 1.00 | 0.00 | |
| Census region (T5) | ||||
| Northeast | 0.18 | 1.00 | 0.00 | |
| Midwest | 0.28 | 1.00 | 0.00 | |
| South | 0.32 | 1.00 | 0.00 | |
| West | 0.22 | 1.00 | 0.00 | |
| Urbanicity (T5) | ||||
| Large and mid-size cities | 0.36 | 1.00 | 0.00 | |
| Large and mid-size suburb and large town | 0.38 | 1.00 | 0.00 | |
| Small town and rural | 0.26 | 1.00 | 0.00 | |
| More than 25% Black students in school – Level 2 (T5) | 0.15 | 1.00 | 0.00 | |
| More than 25% Hispanic students in school – Level 2 (T5) | 0.19 | 1.00 | 0.00 | |
| % eligible for free lunch – Level 2 (T5) | 35.53 | 26.87 | 95.00 | 0.00 |
| Reading in bottom 10% (IRT scale) (T5) | 0.10 | 1.00 | 0.00 | |
| Reading in bottom 10% (IRT scale) (T6) | 0.10 | 1.00 | 0.00 | |
| Math in bottom 10% (IRT scale) (T5) | 0.10 | 1.00 | 0.00 | |
| Math in bottom 10% (IRT scale) (T6) | 0.10 | 1.00 | 0.00 | |
| Approaches to learning – bottom 10% (T5) | 0.12 | 1.00 | 0.00 | |
| Approaches to learning – bottom 10% (T6) | 0.08 | 1.00 | 0.00 | |
| Self-control – bottom 10% (T5) | 0.10 | 1.00 | 0.00 | |
| Self-control – bottom 10% (T6) | 0.06 | 1.00 | 0.00 | |
| Interpersonal skills – bottom 10% (T5) | 0.12 | 1.00 | 0.00 | |
| Interpersonal skills – bottom 10% (T6) | 0.08 | 1.00 | 0.00 | |
| Externalizing behavior problems – upper 10% (T5) | 0.10 | 1.00 | 0.00 | |
| Externalizing behavior problems – upper 10% (T6) | 0.10 | 1.00 | 0.00 | |
| Internalizing behavior problems – upper 10% (T5) | 0.14 | 1.00 | 0.00 | |
| Internalizing behavior problems – upper 10% (T6) | 0.15 | 1.00 | 0.00 |
Note. T1 = fall of kindergarten; T4 = spring of first grade; T5 = spring of third grade; T6 = spring of fifth grade; Level 1 is student level n = 9,324. Level 2 is school level n = 966. AFDC = Aid to Families with Dependent Children; WIC = Special Supplemental Nutrition Program for Women, Infants, and Children; IRT = Item Response Theory.