Table 1.

Descriptive statistics: Mean (Standard Deviation) and group comparisons on individual and socio-demographic variables.

	TD (n = 48)	HR-NDD (n = 42)	t (df)	p	Cohen’s d
Gestational age (weeks)	39.09 (1.29)	38.98 (1.61)	0.371 (78)	0.712	0.083
Socioeconomic status a	68.37 (15.49)	60.26 (18.95)	2.172 (83)	0.033	0.473
Maternal education level b	61.28 (13.61)	54.38 (16.06)	2.170 (85)	0.033	0.467
Paternal education level b	49.36 (16.47)	46.75 (15.26)	0.762 (85)	0.448	0.164

^a 9-point scale, whereby a score ranging 10–90 was assigned to each parental job and the higher of two scores was used when both parents were employed [44]. ^b 9-point ordinal scale, created ad-hoc and based on the Italian school system. In bold the significant differences between groups.