Sample characteristics
| All (N=14 068) | ||||
|---|---|---|---|---|
| Males (51.3%) | Females (48.7%) | Test statistics† | ||
| Mean cognitive ability (SD)‡ | 43.14 (15.91) | 42.01 (16.07) | 44.34 (15.66) | t=−8.71** |
| Mean verbal sub score (SD)‡ | 22.16 (9.26) | 21.15 (9.37) | 23.23 (9.02) | t=−13.44** |
| Mean non-verbal sub score (SD)‡ | 20.98 (7.49) | 20.86 (7.56) | 21.11 (7.43) | t=−1.94* |
| Internalising problems‡ | ||||
| Mean score (SD) | 3.58 (4.24) | 3.83 (4.28) | 3.31 (4.18) | z=−10.20** |
| Somatic symptom‡ score mean (SD) | 0.32 (0.55) | 0.29 (0.54) | 0.34 (0.57) | z=−4.49** |
| Gastric symptom‡ score mean (SD) | 0.25 (0.52) | 0.20 (0.46) | 0.31 (0.57) | z=−12.36** |
| Somatic symptom scores in adulthood | ||||
| Mean score (SD) at age 23 years | 0.76 (1.09) | 0.63 (1.00) | 0.90 (1.16) | z=−14.23** |
| Mean score (SD) at age 33 years | 0.81 (1.14) | 0.74 (1.10) | 0.88 (1.17) | z=−7.19** |
| Mean score (SD) at age 42 years | 1.01 (1.28) | 0.92 (1.23) | 1.11 (1.31) | z=−8.23** |
| Psychological symptom scores | ||||
| Mean score (SD) at age 23 years | 1.92 (2.23) | 1.37 (1.83) | 2.46 (2.46) | z=−26.03** |
| Mean score (SD) at age 33 years | 1.57 (2.18) | 1.25 (1.89) | 1.89 (2.38) | z=−15.17** |
| Mean score (SD) at age 42 years | 2.47 (2.63) | 2.11 (2.45) | 2.81 (2.75) | z=−14.24** |
| CFS at age 42 years | χ2=3.83* | |||
| Yes (N, %) | 103 (0.7) | 41 (0.6) | 62 (0.9) | |
| No (N, %) | 9670 (68.7) | 4786 (66.3) | 4946 (72.2) | |
| CFS-like illness at age 42 years | χ2=34.65** | |||
| Yes (N, %) | 196 (1.4) | 56 (0.8) | 140 (2.0) | |
| No (N, %) | 9593 (68.2) | 4834 (66.9) | 4955 (72.4) | |
| IBS at age 42 years | χ2=171.23** | |||
| Yes (N, %) | 830 (5.9) | 230 (3.2) | 600 (8.8) | |
| No (N, %) | 8352 (59.4) | 4533 (62.8) | 4649 (67.9) | |
| Parental academic expectations§ (%) | χ2=214.28** | |||
| Very anxious | 17.5 | 20.8 | 14.0 | |
| Fairly anxious | 11.3 | 12.6 | 10.0 | |
| Content if tries | 39.4 | 34.3 | 44.8 | |
| Not bothered | 3.5 | 3.3 | 3.7 | |
| Uncertain | 2.1 | 2.3 | 1.8 | |
| Educational aspirations of parents§ (%) | χ2=48.56** | |||
| Leave at a minimum age | 25.7 | 27.4 | 24.0 | |
| Continue full-time education to 18 years | 18.1 | 16.2 | 20.2 | |
| Continue full-time education after 18 years | 23.4 | 23.5 | 23.3 | |
| Uncertain | 4.3 | 4.4 | 4.3 | |
| Parental interest in child's education§ | ||||
| Mother (%) | χ2=28.51** | |||
| Over concerned | 1.4 | 1.7 | 1.1 | |
| Very interested | 25.8 | 24.7 | 27.1 | |
| Some interest | 22.6 | 21.9 | 23.4 | |
| Little or no interest | 11.8 | 12.5 | 11.1 | |
| Cannot say | 9.0 | 9.4 | 8.6 | |
| Inapplicable | 1.0 | 1.1 | .9 | |
| Father (%) | 28.36** | |||
| Over concerned | 1.5 | 1.9 | 1.1 | |
| Very interested | 22.2 | 22.1 | 22.3 | |
| Some interest | 19.1 | 19.1 | 19.1 | |
| Little or no interest | 12.3 | 13.2 | 11.4 | |
| Cannot say | 11.0 | 10.4 | 11.7 | |
| Inapplicable | 2.5 | 2.5 | 2.5 | |
| Parental social class‡ (%) | χ2=.80 | |||
| I/II professional/managerial/technical | 20.9 | 20.6 | 21.3 | |
| III other non-manual | 8.2 | 8.1 | 8.3 | |
| III skilled manual | 37.9 | 38.0 | 37.8 | |
| V and V unskilled manual | 20.6 | 20.5 | 20.7 | |
†Scores in males (1) versus scores in females (2); missing data at 11 years (0.6−21.6%), at 16 years (26.2–31.3%), at 23 years (24.1%), at 33 years (31.1%) and at 42 years (30.4–34.7%).
‡At age 11 years.
§At age 16 years.
CFS, chronic fatigue syndrome; IBS, irritable bowel syndrome.