Descriptive characteristics and early childhood cognitive function scores
| Characteristic | % (n) | Mean±SD |
| Total sample | 8129 | |
| Age, mean±SD | 10.7±0.5 | |
| Male | 49.1 (3992) | |
| White British | 89.2 (7255) | |
| Maternal highest qualification (≥A levels) | 42.7 (3473) | |
| Poverty level income | 27.6 (2243) | |
| Smoked during pregnancy | 25.4 (2062) | |
| SDQ score | 7.0±5.1 | |
| Sport and active games (% regularly) | 59.4 (4827) | |
| Reading for enjoyment (% regularly) | 46.7 (3798) | |
| Gaming on PC/games console (% regularly) | 53.8 (4370) | |
| Online messaging (% regularly) | 21.9 (1779) | |
| Ever smoked (% yes) | 2.3 (184) | |
| Ever consumed alcohol (% yes) | 12.4 (1007) | |
| Verbal ability composite score | 51.0±10.0 | |
| Non-verbal ability composite score | 56.4±10.0 | |
| Spatial ability composite score | 52.9±8.8 |
PC, personal computer; SDQ, Strengths and Difficulties Questionnaire.