Table 1.

Descriptive statistics of study’s variables.

	Full sample		Boys		Girls
	M	SD	M	SD	M	SD	T	df	p
Infant temperament
IBQ 4 m duration of orienting	4.01	1.00	4.11	1.07	3.90	0.93	0.85	67	0.39
IBQ 4 m smile and laughter	4.89	0.93	4.92	1.09	4.87	0.76	0.25	68	0.80
IBQ 4 m distress to limitations	3.35	0.65	3.44	0.62	3.25	0.67	1.17	68	0.25
Maternal input
Types per minute 6 months	11.83	3.39	11.83	3.53	11.83	3.29	0.00	68	0.99
Types per minute 9 months	10.56	2.51	10.28	2.41	10.83	2.61	-0.91	68	0.36
Types per minute 12 months	12.77	2.66	12.47	3.02	13.06	2.25	-0.93	63	0.36
MLU 6 months	2.70	0.41	2.70	0.44	2.70	0.39	0.06	68	0.95
MLU 9 months	2.48	0.39	2.50	0.39	2.46	0.39	0.38	68	0.71
MLU 12 months	2.78	0.39	2.72	0.40	2.83	0.38	-1.23	68	0.23
Child language competences
CDI production 18 months	67.88	75.90	225.30	91.42	267.59	87.61	-1.80	54	0.07
MLU 24 months	1.38	0.37	1.23	0.22	1.50	0.44	-3.03	62	<0.01**

^∗p < 0.05, ^∗∗p < 0.01.