Table 3.

Results of hierarchical regression analyses for factors predicting spatial vocabulary, receptive general vocabulary and grammatical and lexical categories (N = 30 for all analyses).

	Model 1			Model 2
Predictors	B (SE)	β	R2	B (SE)	β	R2	ΔR2
Factors predicting spatial vocabulary
Age of independent walking	-0.02 (0.08)	-0.06	0.004	0.07 (0.08)	0.17	0.20∗	0.19∗
Exploration through self-locomotion				2.47 (0.97)	0.49∗
Factors predicting receptive general vocabulary
Age of independent walking	0.52 (0.81)	0.12	0.12	1.15 (0.89)	0.27	0.10	0.08
Exploration through self-locomotion				17.20 (10.94)	0.32
Factors predicting lexical and grammatical categories
Age of independent walking	-0.02 (0.06)	-0.04	0.002	0.01 (0.09)	0.03	0.02	0.02
Exploration through self-locomotion				0.74 (1.06)	0.15

^∗p ≤ 0.05.