Pardon the sensationalist headline of that article:
Mark says that "one thing that might explain the higher numbers here—in case people question my methods—is that I used a tarantula." Apparently, people seemed pretty eager about hitting a spider. "If you take that out it goes to 2.8% which is closer to the other turtle vs. snake studies I ended up finding."
It is still quite a surprisingly high number. At least compared to a 2008 study using the Psychopathy Checklist, which discovered that 1.2 percent of the US population were potential psychopaths. 1.2 vs 2.8 is a huge difference.
I was not aware of the other turtle and snake studies.
Note that with turtle this is the lower bound on percentage of evil; a perfectly amoral person that could e.g. kill for modest and unimportant sum of money or any other reason would still have no incentive to steer to drive over a turtle; and a significant percentage of people would simply fail to notice the turtle entirely.
This gives interesting prior for mental model of other people. Even at couple percent, psychopathy is much more common than notable intelligence or many other situations considered 'rare' or 'unlikely'. It appears to me that due to the politeness and the necessary good-until-proven-evil strategy, many people act as if they have an incredibly low prior for psychopathy, which permits easy exploitation by psychopaths. There may also be signaling reasons for pretending to have very low prior for psychopathy as one of the groups of people with high prior for psychopathy is psychopaths themselves; pretending easily becomes too natural, though.
Perhaps adjusting the priors could improve personal safety and robustness with regards to various forms of exploitation, whenever the priors are set incorrectly.
I squash bugs for the hell of it sometimes. Squashing things can be satisfying. I guess that means I'm a psychopath (really should be sadist, right?) too?
It certainly feels like I empathize with people at times, and my goals are quite altruistic. But I don't empathize much with bugs. I'm a little skeptical they feel anything that I would classify as pain. How much nervous tissue do they have, really?
Could you put me in a situation where I had the same kind of lack of empathy for larger creatures or even humans? Possibly. I don't have strong inhibitions against this mindset, but that may be because I don't have strong inhibitions against "forbidden thoughts" in general. For example, I don't revile pedophiles like you're supposed to in US culture. (Although this may not be a very high bar relative to LW.)
Note also that this is my alt account, soon to be deleted. Maybe other reasonable, friendly people without alt accounts would also squash bugs but are afraid of explaining themselves for fear of being labeled sadists.
Yeah, but when I'm in such a mood I usually use plastic glasses.