Table 4.

Interrater Reliability of Family History Reports of Gambling Behavior Across Twin Pairs.

Gambling Behavior	Father	Mother
Ever Gambled
Kappa	0.40 (.35 – .46)	0.41 (.36 – .47)
Yule’s Y	0.49 (.43 – .54)	0.48 (.43 – .53)
Gambled Monthly
Kappa	0.38 (.33 – .44)	0.40 (.34 – .46)
Yule’s Y	0.39 (.33 – .45)	0.40 (.34 – .46)
Gambled Weekly
Kappa	0.25 (.08 – .43)	0.28 (.10 – .45)
Yule’s Y	0.37 (.15 – .55)	0.39 (.18 – .57)
Gambling Problem
Kappa	0.50 (.37 – .62)	0.47 (.30 – .63)
Yule’s Y	0.74 (.65 – .81)	0.78 (.68 – .87)

Note: N = 1,750 twin pairs.