Table 1.
Sample characteristics
|
All twins |
|
|---|---|
| (n = 692) | |
| Children’s sex |
|
| Boys |
48.0% |
| Girls |
52.0% |
| Zygosity |
|
| MZ |
42.5% |
| DZ |
57.5% |
| Children’s age (years)1 |
|
| T1 |
2.65 ± 0.08 |
| T2 |
8.97 ± 0.54 |
| Ethnicity (mother) |
|
| White |
89.9% |
| Non-white |
6.4% |
| Ethnicity missing |
3.8% |
| Parental education2 – T1 |
|
| No high school diploma |
10.4% |
| High school diploma |
7.2% |
| College diploma |
35.3% |
| University diploma |
41.9% |
| Education missing |
5.2% |
| Annual family income ($Can) – T1 |
|
| < 20,000 |
9.2% |
| 20,000-39,999 |
20.2% |
| 40,000-59,999 |
22.5% |
| ≥ 60,000 |
41.3% |
| Income missing | 6.6% |
1Mean ± SD.
2Represents the highest educational level for either parent.