Table 2.

Mean (standard deviation) of all lexical measures and group comparisons of young and older participants.

Variable	Older	Young	t or U	p	Cohen's d
Filler words	5.49 (2.56)	4.32 (2.42)	t = 2.33	.023	0.48
Pronoun	7.28 (2.41)	4.64 (2.24)	t = 5.57	< .001	1.14
Verb	22.52 (3.47)	20.48 (3.41)	t = 2.96	.004	0.6
Preposition	10.03 (1.97)	11.85 (2.89)	U = 902	.002	0.69
Conjunction	4.34 (1.84)	5.3 (1.95)	t = −2.55	.013	0.5
Determiner	14.27 (2.5)	15.7 (3.07)	t = −2.65	.009	0.49
Noun	20.36 (4.38)	21.59 (2.91)	U = 1083.5	.049	0.36
Adjective	5.61 (1.83)	5.62 (2.5)	t = 0.02	.98	0
Adverb	5.63 (2.12)	5.56 (2.67)	t = 0.37	.71	0.07
Familiarity (noun)	2.36 (0.03)	2.34 (0.03)	t = 2.73	.008	0.55
Familiarity (verb)	2.29 (0.05)	2.25 (0.05)	t = 4.1	< .001	0.8
Frequency (noun)	3.57 (0.17)	3.6 (0.15)	t = −0.9	.37	0.19
Frequency (verb)	4.54 (0.25)	4.38 (0.23)	t = 3.19	.002	0.66
Ambiguity (noun)	1.69 (0.06)	1.71 (0.06)	t = −2	.049	0.39
Ambiguity (verb)	2.11 (0.05)	2.13 (0.05)	t = −1.93	.057	0.37
Concreteness (noun)	4.49 (0.23)	4.43 (0.21)	t = 1.43	.16	0.3
Concreteness (verb)	2.6 (0.18)	2.65 (0.21)	t = −1.2	.23	0.23
AoA (noun)	4.42 (0.32)	4.53 (0.37)	t = −1.59	.12	0.3
AoA (verb)	4.7 (0.24)	4.75 (0.2)	t = −0.97	.34	0.2
Tense-inflected verb	12.39 (1.86)	11.06 (1.82)	t = 3.59	< .001	0.73
Vocabulary diversity	0.68 (0.00)	0.69 (0.01)	U = 968.5	.008	0.40
MLC	8.26 (1.32)	9.33 (1.85)	t = −3.52	< .001	0.63
Total words	176.57 (64.98)	136.39 (48.98)	t = 3.33	.002	0.73

Note. Part-of-speech counts and the number of tense-inflected verbs are per 100 words. AoA = age of acquisition; MLC = mean length of clause.