There would be quite a few measures that could apply. Which one you prefer will depend in part on who you're studying and in part on whether you care more about attitudes or behaviors. Anyway, here are a few (just a few!) suggestions:
Scott Lilienfeld's "Psychopathic Personality Inventory" was first described in the Journal of Personality Assessment in 1996. It's been used quite a bit.
Daniel Boduszek of the University of Huddersfield recently (2016) published a "Psychopathic Personality Traits Scale" - see the Journal of Criminal Justice.
Both of those are mainly geared toward offender populations, I think.
Michael Levenson introduced a psychopathy scale intended for non-criminal groups (such as college students) in 1995. It's also been used quite a bit over the years. The original paper was in the Journal of Personality and Social Psychology.
Hans J. Eysenck's Psychoticism scales (such as that on the 1994 EPQ-R) mainly measure antisocial attitudes. One nice thing about these scales is that item content is almost entirely non-pathological, so it isn't as obvious what you're getting at and your studies won't be contaminated by psychopathology if that isn't what you want.
Finally, one must give a nod to the MMPI-2 Psychopathic Deviate scale (Scale 4).
Surely one of these will be appropriate for your project, whatever it may be.
The MINI International Neuropsychiatric Interview has a stand-alone Antisocial Personality Disorder test consisting of six questions about behaviors before the age of 15-years old and six questions after the age of 15-years old. The reference for this test is: MINI International Neuropsychiatric Interview, version 5.0.0; USA authors: D. Sheehan, J. Janavs, R. Baker, K. Harnett-Sheehan, E. Knapp, M. Sheehan. French authors: Y. Lecrubier, E. Weiller, T. Hergueta, P. Amorim, L.I. Bonora, J.P. Lepine. Copyright 1992, 1994, 1998, 2000.
In addition, the Hare Psychopathy Checklist-Revised (PCL-R) by R.D. Hare might work for you.
Is there a "dark personality test?" I thought the people investigating this domain were using existing measures of the three constructs involved. But I agree that measuring all three of these "normal" but shady characteristics might enrich Eric's research.
Hare's PCL-R is the gold standard of psychopathy assessment, but it's a lengthy semi-structured interview that requires training to use properly.
Hi, Steven, yes, there is 41 item original questionnaire, a more concise 27 (short dark triad), and a "dirty dozen", which I find a bit too straigh-forward
the MMPI (Minnesota Multiphasic Personality Inventory) is designed to also measure psychopathologies. The BPI could pick this up as well. while i have done case analysis on several people with APD, in-depth interviews especially regarding one's developmental history is most useful. hope this will help you
Michael Seto has covered all the well-validated measures. If you are looking at psychopathy, there is a self-report measure: Paulhus, D., Neumann, C.S. & Hare, R.D. (2016). Self-Report Psychopathy Scale 4th Edition. Multi-Health Systems. The technical manual has plenty in terms of validation.