Table 7.

Statistics for sum scores of parent-report measures and survey subscales

Measure	Mean (SD)	Internal Consistency (Cronbach’s α)
Personality
EPQ-SF: Neuroticism (about self)	3.18 (3.03)	0.92
EPQ-SF: Extraversion (about self)	4.41 (2.57)	0.93
ICU (about twin)	20.03 (9.33)	0.91
Nicotine Use (about use)
Fagerstrom Test for Nicotine Dependence	3.45 (2.66)	0.60
Alcohol Use (about self)
DEP: Assertion	28.38 (7.84)	0.88
DEP: Affective change	20.26 (6.05)	0.89
DEP: Dependence	13.50 (4.31)	0.81
DEP: Sexual enhancement	16.30 (2.89)	0.52
DEP: Cognitive change	7.25 (2.34)	0.77
DEP: Tension reduction	10.44 (3.29)	0.67
AUDIT	3.12 (2.51)	0.82
Other
PCL-5: this month (about self)	6.46 (9.21)	0.95
PCL-5: lifetime (about self)	8.92 (11.22)	0.96

Note: DASS=Depression, Anxiety, Stress Scale-21, AUDIT= Alcohol Use Disorders Identification Test, DEP=Drinking Expectancy Profile EPQ-SF= Eysenck Personality Questionnaire- Short Form, ECR-R=Experiences with Close Relationships-Revised, PCL-5=Post-Traumatic Stress Disorder Checklist for DSM-5, ICU=Inventory of Callous-Unemotional Traits