Table 1. Personal and Family Characteristics of the Overall Sample vs Study Sample at Age 6 Years.
| Characteristica | Mean (SD) [Range] |
|---|---|
| Child IQ | 9.0 (2.13) [0-13] |
| Education, y | |
| Mother | 10.5 (2.79) [2-24] |
| Father | 10.6 (2.31) [1-24] |
| Occupational prestige | |
| Mother | 38.6 (12.10) [19.92-85.75] |
| Father | 39.4 (12.86) [21.24-78.34] |
| Age at birth of first child, y | |
| Mother | 25.3 (4.66) [11.81-40.65] |
| Father | 28.4 (5.58) [13.75-50.95] |
| Intact family, No. (%) | 550 (80.0) |
| Overall family adversity index | 0.3 (0.25) [0-1] |
| Siblings, No. (%) | |
| 0 | 240 (26.8) |
| 1-2 | 600 (67.4) |
| ≥3 | 50 (5.8) |
| Behavior at age 6 y | |
| Inattention | 2.66 (2.34) [0-8] |
| Hyperactivity | 1.36 (1.46) [0-4] |
| Opposition | 2.47 (2.58) [0-10] |
| Aggression | 1.29 (1.74) [0-6] |
| Prosociality | 8.0 (4.96) [0-20] |
a
Up to 13.2% missing data, except for intact family, which had 26.0% missing data. In accordance with Statistics Canada data protection requirements, percentages are rounded to 1 decimal point, and counts are rounded to base 10.