Table 6.
Decomposition of statistically significant correlations between anthropometric traits and full-scale IQ into additive genetic and specific environmental factors.1
| Additive genetic correlation | Specific environmental correlation | |||||
|---|---|---|---|---|---|---|
| r | 95% CI | % explained | r | 95% CI | % explained | |
| Boys 11 years of age | ||||||
| Craniological measures | ||||||
| Head circumference | 0.32 | 0.14-0.50 | 78 | 0.21 | 0.09-0.33 | 22 |
| Head length 1 | 0.20 | −0.03-0.51 | 100 | - | ||
| Head length 2 | 0.38 | 0.17-0.65 | 100 | - | ||
| Head breadth | 0.26 | 0.06-0.51 | 100 | - | ||
| Height measures | ||||||
| Total height | 0.19 | 0.03-0.37 | 77 | 0.22 | 0.10-0.34 | 23 |
| Buttock-knee height | 0.34 | 0.13-0.62 | 100 | - | ||
| Knee height | 0.24 | 0.09-0.43 | 100 | - | ||
| Foot length | 0.17 | 0.01-0.36 | 77 | 0.19 | 0.07-0.32 | 23 |
| Girls 11 years of age | ||||||
| Craniological measures | ||||||
| Head circumference | 0.28 | 0.13-0.46 | 100 | - | ||
| Head length 1 | 0.34 | 0.20-0.53 | 100 | - | ||
| Head length 2 | 0.27 | 0.10-0.46 | 100 | - | ||
| Head breadth | 0.22 | 0.08-0.38 | 84 | 0.15 | 0.02-0.27 | 16 |
| Boys 17 years of age | ||||||
| Craniological measures | ||||||
| Head circumference | 0.25 | 0.10-0.42 | 100 | - | ||
| Head length 1 | 0.24 | 0.08-0.43 | 100 | - | ||
| Head length 2 | 0.26 | 0.02-0.58 | 100 | - | ||
| Head breadth | 0.15 | 0.01-0.32 | 100 | - | ||
| Height measures | ||||||
| Total height | 0.14 | 0.00-0.30 | 100 | - | ||
| Knee height | 0.16 | 0.03-0.31 | 100 | - | ||
| Girls 17 years of age | ||||||
| Craniological measures | ||||||
| Head circumference | 0.17 | 0.04-0.30 | 100 | - | ||
| Head length 1 | 0.25 | 0.11-0.41 | 100 | - | ||
1
ACE models without common environmental correlations were used for all traits.