Table 5.

Correlations between the background variables age, NVIQ, SES, and receptive vocabulary and the dependent variables backward Digit Span task, backward Dot Matrix task, Sky Search task, and the positive flanker effect.

	Age	NVIQ	SES	PPVT	Backward Digit Span	Backward Dot Matrix	Sky Search	Positive flanker effect
Age		-0.10	-0.06	-0.18∗	0.30∗∗	0.32∗∗	-0.32∗∗	-0.24∗∗
NVIQ			0.12	0.24∗∗	0.25∗∗	0.28∗∗	-0.11	-0.16
SES				0.15∗	0.05	0.08	0.08	-0.08
PPVT					0.16∗	0.17∗	-0.10	-0.22∗
Backward DS						0.37∗∗	-0.22∗∗	-0.26∗∗
Backward DM							-0.29∗∗	-0.32∗∗
Sky Search								0.12

NVIQ, standardized non-verbal intelligence score; SES, socioeconomic status; PPVT, Peabody Picture Vocabulary Test (Dutch receptive vocabulary, standardized score); ^∗p < 0.05, ^∗∗p < 0.01. Note that the correlations for the positive flanker effect are based on a somewhat smaller sample size, because the children with negative flanker effects are excluded.