Perceptual Bias in Moral Judgments

This is interesting ( I have no answer either, may be mirror neurons?):

"I'm currently working on a project with some students of mine and I've found something surprising that I'd like some feedback on. We've been conducting an eye tracking study, where the goal has been to see if various aspects of participants' looking behavior (where they look first, how long they look, etc.) predicts their moral judgments about whether they wouldshould do x (with the x varying between cases - we're using the trolley, the footbridge, and the baby/villager cases). and whether they

Specifically, participants were given the vignette (the trolley, footbridge, or baby/villager cases) to read on a screen and then two images were flashed immediately after side-by-side for 10 seconds -- in the trolley/footbridge cases, the two images were of a "fat guy" and a group of workers, in the baby/villager case it was a baby and some "villagers". The side which each image shows up on was counterbalanced.

We've found a variety of interesting things with respect to people's looking behaviors and their moral judgments -- but I'm writing this post because I found something even more interesting...and puzzling. Leaving people's actual looking behavior aside, I found a very powerful effect -- consistent across all the vignettes -- for which side of the screen the potential victim (the fat guy or the baby) was on. When the victims were on the right-side of the screen, people's would and should judgements were significantly higher (i.e., they were more willing to, and thought more strongly that they should, kill the victim to save the others), than when they were on the left-side of the screen.

So, does anyone have any suggestions as to what might explain this finding? (e.g., is the "left-brain" a better utilitarian than the right??) Anyone ever heard of this sort of perceptual bias? Got any suggested readings? We're going to be attempting to replicate these findings in a follow-up study this fall, but in the mean time I'd sure like to have a better grip on what it is that might be going on...and why!"