Table 1.
Participant characteristics and descriptive statistics
| Variable | Min | Max | M | SD | |
|---|---|---|---|---|---|
| Gender (% boys/girls) (N = 1181) |
|
|
52.3/47.7 |
|
|
| Age in years (N = 1181) |
3.1 |
3.9 |
|
3.5 |
0.1 |
| Mothers’ edu. (in years) (N = 1132) |
9 |
18 |
|
15.2 |
2.4 |
| Fathers’ edu. (in years) (N = 1087) |
9 |
18 |
|
14.5 |
2.6 |
| Mothers’ age (N = 1180) |
19 |
43 |
|
30.6 |
4.3 |
| ADHD symptoms (N = 1181) |
0 |
18 |
|
4.0 |
3.9 |
| ODD symptoms (N = 1181) |
0 |
8 |
|
1.4 |
1.5 |
| IQ (N = 1181) |
67 |
130 |
|
101.9 |
9.2 |
| Verbal ability (N = 1181) |
2 |
17 |
|
9.7 |
2.1 |
| Nonverbal ability (N = 1181) |
4 |
18 |
|
10.9 |
2.0 |
| VWM (N = 1125) |
2 |
16 |
|
10.8 |
2.9 |
| NVWM (N = 1174) |
2 |
17 |
|
10.4 |
2.8 |
| Response inhibition (N = 1031) |
0 |
30 |
|
14.7 |
8.4 |
| Reported expr. language (N = 1067) | 8 | 50 | 41.6 | 7.3 |
Note. Edu. = education. Mothers’ age = age in years at the time of childbirth. Symptoms = number of symptoms. IQ = abbreviated IQ score estimated from the verbal ability and nonverbal ability subtasks from the Stanford-Binet-5 (SB-5). VWM = verbal working memory from SB-5. NVWM = nonverbal working memory from SB-5. The SB-5 subtask scores were standardized, with Mean = 10 and SD = 3. Response inhibition = statue task (NEPSY), raw scores. Reported expr. language = reported expressive language = CDI from preschool teachers, raw scores.