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% |