Table 1.
Number of Girls and Boys, Mean and Standard Deviation (SD) of Age (months) for Cohorts that Began Longitudinal Study in Grade 1 (Younger) or in Grade 3 (Older), Ethnicity, and Parental Levels of Education
| Grade | Younger Cohort | Older Cohort | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| N | Girls | Boys | Age | N | Girls | Boys | Age | |||
| Mean | SD | Mean | SD | |||||||
| 1 | 128 | 71 | 57 | 82.72 | 3.80 | -- | -- | -- | -- | -- |
| 2 | 124 | 69 | 55 | 92.75 | 3.74 | -- | -- | -- | -- | -- |
| 3 | 122 | 68 | 54 | 104.24 | 3.64 | 113 | 57 | 56 | 106.01 | 3.70 |
| 4 | 119 | 67 | 52 | 116.51 | 3.74 | 110 | 57 | 53 | 116.02 | 3.67 |
| 5 | 114 | 62 | 52 | 128.36 | 3.70 | 106 | 54 | 52 | 127.56 | 3.75 |
| 6 | -- | -- | -- | -- | -- | 106 | 53 | 53 | 139.75 | 3.74 |
| 7 | -- | -- | -- | -- | -- | 99 | 50 | 49 | 151.29 | 3.73 |