TABLE 1.
Characteristics of The Generation R Study population
| Mean | SD | n | % | |
|---|---|---|---|---|
| Child characteristics | ||||
| Sex | ||||
| Boy | 1,105 | 46.0 | ||
| Girl | 1,296 | 54.0 | ||
| Age child at academic assessment (years) | 11.88 | 0.46 | ||
| Age child at IQ assessment (years) | 13.58 | 0.30 | ||
| Mean age difference between assessments (years) | 1.70 | 0.54 | ||
| Ethnicity | ||||
| Dutch | 1,670 | 69.5 | ||
| Non‐Dutch Western | 214 | 8.9 | ||
| Non‐Western | 512 | 21.3 | ||
| Missing | 5 | 0.2 | ||
| IQ | 105.92 | 12.33 | ||
| Academic achievement a | 0.00 | 1.00 | ||
| IQ‐achievement discrepancy a | 0.00 | 1.00 | ||
a
Both academic achievement and the IQ‐achievement discrepancy are standardized.