Table S5.
Statistics for comparison between related and unrelated control subgroups on six control variables and on the childhood-vocabulary test
| Variable | Statistical test | Descriptive statistic | |||
| Related subgroup | Unrelated subgroup | ||||
| N (%) | Mean (SD) | N (%) | Mean (SD) | ||
| Age (y) | t(27) = 0.13, P = 0.90 | 15 | 32 (6) | 14 | 32 (8) |
| Education* | χ2(3) = 4.72, P = 0.19 | ||||
| VBO | 1 (7) | — | 1 (7) | — | |
| MAVO | 5 (33) | — | 2 (14) | — | |
| HAVO | 4 (27) | — | 1 (7) | — | |
| VWO | 5 (33) | — | 10 (71) | — | |
| Visit | χ2(1) = 0.32, P = 0.57 | ||||
| Yes | 7 (47) | — | 8 (57) | — | |
| No | 8 (53) | — | 6 (43) | — | |
| Visit ratio | t(27) = −0.37, P = 0.71 | 15 | 0.01 (0.02) | 14 | 0.01 (0.02) |
| Language | t(27) = −0.29, P = 0.78 | 15 | 2.5 (1.1) | 14 | 2.6 (0.9) |
| Sex | χ2(1) = 0.91, P = 0.34 | ||||
| Female | 7 (47) | — | 9 (64) | — | |
| Male | 8 (53) | — | 5 (36) | — | |
| Childhood-vocabulary | t(27) = 0.89, P = 0.38 | 15 | 5 (1.0) | 14 | 4.6 (1.2) |
*
From lowest to highest level in the Dutch high school system.