Rolf Degen summarizing: 38% of subjects derived pleasure from purportedly grinding live bugs, some demanded even more than they had been granted

Psychopathy subfactors distinctively predispose to dispositional and state-level of sadistic pleasure.. Jill Lobbestael, Martijn van Teffelen, Roy F. Baumeister. Journal of Behavior Therapy and Experimental Psychiatry, https://doi.org/10.1016/j.jbtep.2019.02.003

Highlights
•    Sadistic pleasure has devastating interpersonal and societal consequences.
•    The current knowledge on non-sexual, subclinical forms of sadistic pleasure is poor.
•    Coldheartedness showed the strongest relationship to sadistic pleasure.
•    Increased Coldheartedness related to more pleasure and less guilt after bug grinding.

Abstract
Background and objectives: Sadistic pleasure — the enjoyment of harm-infliction to others — can have devastating interpersonal and societal consequences. The current knowledge on non-sexual, subclinical forms of sadistic pleasure is poor. The present study therefore focussed on the personality correlates of sadistic pleasure and investigated the relationship between the different subcomponents of psychopathy and both dispositional and state-level sadistic pleasure.

Method: N = 120 males drawn from a community sample filled out questionnaires to assess their level of psychopathy and dispositional sadism. Then, participants engaged in a bug-grinder procedure in which they were led to believe that they were killing pill bugs. The positive affect they reported after ostensibly killing the bugs served as measures of sadistic pleasure. The bug-grinding task was repeated a second time after installing either a positive victim attitude combined with giving human names to the bugs, or a negative victim attitude combined with labeling the bugs with numbers.

Results: Although the Self-centred Impulsivity component of psychopathy had some relevance to sadism, it was the Coldheartedness subscale that showed the strongest relationship to sadistic pleasure. Specifically, increased Coldheartedness was uniquely related to more positive affect, along with less guilt after bug grinding.

Limitations: Drawbacks of the study include the unique reliance on a male, community sample, and the potential impact of demand characteristics, including a suggestion that the participant put at least some bugs into the grinder.

Conclusions: Our findings underscore the differential predictive value of psychopathy components for sadistic pleasure. Coldheartedness can be considered especially disturbing because of its unique relationship to harm-infliction of the most irreversible nature (i.e. killing), and gaining pleasure out of it.