Table 4.

Results of tests for zero-order correlates with language growth

Outcome	Predictor	t for intercept	t for slope
Expressive	Intentional communication	5.4***	4.9***
	Consonant inventory	4.5***	3.7***
	Responding to joint attention	4.2***	4.2***
	Developmental ratio	3.7***	3.5***
	Play	3.1**	2.6**
	Autism symptomotology (reflected)	2.7**	2.5*
	Parental linguistic responses	2.3*	2.7**
	Motor imitation	2.1*	1.5
	Estimated receptive vocabulary	2.0*	1.7
	Attention to child-directed speech	1.4	1.2
	Nonimitative oral motor	1.09	.93
Receptive	Responding to joint attention	5.1***	3.3***
	Receptive vocabulary	5.0***	.0
	Intentional communication	4.2***	1.8
	Autism symptomotology (reflected)	3.9***	3.7***
	Developmental ratio	3.9***	2.6**
	Play	3.6*	1.8
	Attention during child-directed speech	3.4***	2.3*
	Parent linguistic responses	2.3**	2.0*

^*p < .05;

^**p < .01;

^***p < .001