Table 2. Regression coefficients (95% confidence intervals) for AH4 score (age 28 or 35) and mean choice reaction time (age 35) according to father's and mother's age (in years) at respondent's birth.
| Adjusted for age at IQ measurement | Adjusted for age at IQ measurement and other parent's age at birth | |
| AH4 score | ||
| Paternal age (linear term) | 1.57 (0.65, 2.50) | 1.48 (0.18, 2.77) |
| Paternal age (quadratic term) | −0.02 (−0.04, −0.01) | −0.02 (−0.04, −0.01) |
| P 1 | 0.002 | 0.02 |
| Maternal age (linear term) | 1.09 (−0.01, 2.18) | −0.07 (−1.58, 1.44) |
| Maternal age (quadratic term) | −0.02 (−0.04, 0.00) | 0.01 (−0.02, 0.03) |
| P 1 | 0.02 | 0.19 |
| Reaction time | ||
| Paternal age (linear term) | −5.40 (−11.91, 1.10) | −3.92 (−13.03, 5.20) |
| Paternal age (quadratic term) | 0.08 (−0.02, 0.18) | 0.05 (−0.09, 0.19) |
| P 1 | 0.21 | 0.63 |
| Maternal age (linear term) | −5.92 (−12.98, 1.14) | −2.75 (−13.31, 7.81) |
| Maternal age (quadratic term) | 0.10 (−0.02, 0.22) | 0.05 (−0.12, 0.23) |
| P 1 | 0.21 | 0.77 |
1
p for model including both linear and quadratic terms based on likelihood ratio test.