The APSD is a 20-item scale measuring psychopathic traits. This measure was formerly known as the Psychopathy Screening Device.

Some references are below:

• Frick, P.J., Bodin, S.D., & Barry, C.T. (2000). Psychopathic traits and conduct problems in community and clinic-referred samples of children: Further development of the psychopathy screening device. Psychological Assessment, 12, 382-393.
• Poythress, N.G., Douglas, K.S., Falkenbach, D., Cruise, K., Lee, Z., Murrie, D.C., & Vitacco, M. (2006). Internal consistency reliability of the self-report antisocial process screening device. Assessment, 13, 107-113.
• Frick, P.J., O’Brien, B.S., Wootton, J.M., & McBurnett, K. (1994). Psychopathy and Conduct Problems in Children. Journal of Abnormal Psychology, 103, 700-707.

Citation reference:

• Frick, P.J., & Hare, R.D. (2001). The Antisocial Process Screening Device. Toronto, Ontario, Canada: Multi-Heath Systems.

Responses on the APSD are 'Not at all True”, 'Somewhat True” and 'Certainly True”. Items 3, 7, 12, 18 and 20 are reverse scored.

There are three scales that have been validated and are consistent on the parent and teacher report:

• Narcissism (items 5, 8, 10, 11, 14, 15, 16)
• Impulsivity (items 1, 4, 9, 13, 17)
• Callous-unemotional (items R3, R7, R12, R18, 19, R20)

Items 2 and 6 have not been unclassified into any of the subscales. High scores indicate more narcissistic, impulsive and callous-unemotional traits.