Table 2.

Descriptive statistics for raw and transformed psychopathy scores

Wave (Age)	Descriptives for raw scores			Descriptives for transformed scores
	Mean	Standard Deviation	Skewness	Mean	Standard Deviation	Skewness
1 (7.0)	0.43	0.29	0.76	0.86	0.35	−0.33
2 (7.5)	0.38	0.31	1.08	0.78	0.39	−0.16
3 (8.0)	0.35	0.29	1.15	0.74	0.39	−0.21
4 (8.5)	0.36	0.29	1.11	0.75	0.39	−0.19
5 (9.0)	0.36	0.30	1.33	0.75	0.39	−0.12
6 (9.5)	0.32	0.30	1.42	0.68	0.41	0.03
7 (10.0)	0.41	0.34	1.11	0.80	0.42	−0.13
8 (10.5)	0.37	0.33	1.13	0.74	0.42	−0.07
9 (11.0)	0.37	0.32	1.11	0.76	0.41	−0.08
10 (11.5)	0.36	0.31	1.30	0.76	0.40	−0.12
11 (12.0)	0.37	0.33	1.28	0.75	0.42	−0.01
12 (12.5)	0.37	0.32	1.15	0.76	0.41	−0.07
13 (13.0)	0.41	0.35	1.08	0.81	0.42	−0.09
14 (13.5)	0.42	0.32	1.01	0.84	0.38	−0.14
15 (14.0)	0.37	0.34	1.35	0.75	0.42	0.01
16 (14.5)	0.38	0.32	1.06	0.78	0.39	−0.05
17 (15.0)	0.35	0.35	1.45	0.71	0.44	0.19
18 (15.5)	0.35	0.35	1.33	0.70	0.45	0.13
19 (16.0)	0.34	0.34	1.43	0.71	0.43	0.23
20 (16.5)	0.34	0.35	1.46	0.70	0.44	0.20
21 (17.0)	0.31	0.34	1.54	0.65	0.45	0.25
22 (17.5)	0.33	0.32	1.34	0.70	0.43	0.07

Note: The columns under “Descriptives for raw scores” pertain to the psychopathy scores prior to the square-root transformation described in footnote 2, while the columns under “Descriptives for transformed scores” pertain to the psychopathy scores after the transformation. Skewness is the sample third central moment, divided by the sample variance raised to the 3/2 power. Skewness greater than 1 or less than −1 indicates considerable asymmetry (and, hence, non-normality) in the distribution of sample values.