Bartels and Pizarro: Consequentialists Are Psychopaths
... or at least they tend that direction on personality tests.
There are, I think, some gaps in the Bartels and Pizarro argument -- especially since there might be a pretty loose connection between real consequentialist moral thinking and tending to say "push the fat man!" when given a trolley problem. Quite possibly, undergraduates tending toward psychopathic personality will say the latter even if they aren't very good representatives of genuine consequentialist moral thought.
Josh Rust and I, in our study of the moral behavior of ethics professors, found that ethicists favoring deontology vs. consequentialism vs. virtue ethics all behaved about the same, both by self-report measures and by direct observational measures. To the extent there was a tendency, it was for virtue ethicists to self-report slightly worse behavior.
Update, Sept 28: In the comments I think I more clearly articulated my concern about Bartels and Pizarro than I did above, so I paste it here: "As a cartoon, imagine that you have a group of respondents who don't really think ethically about the dilemmas at all and just think it's funny to tell the prof to push the fat man, and suppose that psychopathic personality types are overrepresented in that group. Then you get the Bartels and Pizarro results, but there's no relationship with consequentialist thinking."