TABLE 1.
Parental and Child Characteristics by Trajectory Group
| Variable | Trajectory Group
|
P Value on χ2 Joint Test of Significance (df = 2) | P Value on t Tests of High vs Low and Medium (df = 1) | ||
|---|---|---|---|---|---|
| Low | Medium | High | |||
| N | 140 | 294 | 70 | N/A | N/A |
| At birth, % | |||||
| Male | 38.6 | 50.3 | 58.6 | .012 | .032 |
| Young siblings | 16.4 | 40.8 | 57.1 | <.001 | <.001 |
| Low income | 20.5 | 20.2 | 43.9 | <.001 | <.001 |
| Parents separated | 3.7 | 3.2 | 11.8 | .025 | <.001 |
| Early motherhood | 22.8 | 22.2 | 42.4 | .004 | <.001 |
| Young mother now | 26.2 | 20.0 | 31.3 | .094 | .048 |
| Mother no high school diploma | 5.3 | 9.7 | 15.4 | .071 | .036 |
| Mother antisocial (before end of high school) | .1 | 4.9 | 14.0 | .016 | .003 |
| Mother smoked (during pregnancy) | 20.1 | 22.1 | 38.2 | .014 | .003 |
| Mother drank alcohol (during pregnancy) | 3.0 | 5.0 | 4.4 | .93 | .479 |
| Maternal postpartum depression | 17.9 | 16.6 | 29.4 | .067 | .008 |
| Father antisocial (before end of high school) | 13.6 | 11.2 | 12.9 | .768 | .418 |
| At 5 mo of age, % | |||||
| High family dysfunction | 32.8 | 29.2 | 53.8 | .001 | <.001 |
| Mother coercive parenting | 8.1 | 12.1 | 31.3 | .001 | <.001 |
| Mother feels ineffective | 18.3 | 17.5 | 20.9 | .814 | .271 |
| Difficult temperament | 25.4 | 21.2 | 40.0 | .010 | .003 |