Table 1.

Demographics and descriptive statistics for each sample.

	Sample 1 (N = 66)	Sample 2 (N = 94)	Sample 3 (N = 49)
% Female	76.9%a	59.6%b	77.6%a
Age (SD)	19.83 (2.76)a	19.39 (2.25)a,b	18.82 (1.41)b
Task RSA (SD)	6.44 (1.38)a	6.91 (1.01)b	6.74 (1.34)a,b
Rest RSA (SD)	–	6.66 (1.05)a	6.93 (1.46)a
Ethnicity
African American	12.3%a	8.5%a	12.2%a
Caucasian	41.5%a	34.0%a	26.5%a
Asian	23.1%a	21.3%a	22.4%a
Hispanic/Latino	15.4%a	27.7%a	30.6%a
Other	7.7%a	8.5%a	6.1%a

Note. Means or percentages with different subscripts across rows were significantly different in pairwise comparisons (p < .05, chi-square test for categorical variables and Tukey’s honestly significant difference test for continuous variables). SD = standard deviation; RSA = respiratory sinus arrhythmia; Task RSA = RSA during the startle task; Rest RSA = RSA collected at rest prior to the startle task.