Ethical feelings are weakened by the belief that human behaviour is determined by environmental and genetic factors. This has been shown in a psychological experiment at the Carlson School of Marketing, University of Minnesota, finding that encouraging the belief in determinism increases cheating.
Oh yes, this not only proves the old French saying to be true: "Tout comprendre, c'est tout pardonner." It also gives a good reason to my personal reaction whenever I hear someone trying to "understand" why a rapist, pedophiliac or amok killer committed his crime.
Cheaters in two experiments
In a first experiment, students had to solve math problems that were presented by a computer program with a built-in flaw, "erroneously" allowing students to view the solutions. Prior to the test, students have been given either a text describing human behaviour as a consequence of environmental and genetic factors or a neutral text not supporting a deterministic view. Those who have read the deterministic text cheated more than the others.
In a second experiment, students had to assess their own reward for performing a cognitive task. Again, they have read a text before, either supporting determinism or a free will. Those indoctrinated by determinism tended to cheat by overpaying themselves, those who have been convinced of a free will did not cheat.
In philosophy, there have been many disputes about the subject. Some have rejected free will because they have been aware that a wide range of human behaviour is determined by internal and external causes. Others have rejected determinism because they feared a loss of ethics, a fear that is supported by the above experiments.
The most reasonable view has been formulated more than three hundred years ago by Thomas Hobbes, stating that free will is compatible with external or internal forces that coerce a person to do something, possibly against his own free will. The forces may be too strong to be overridden, but they do not exclude a free will. Free will is what makes us subjects, otherwise we'd be no more than bio-robots. I even won't exclude the possibility that some animals may have a free will, at least from their subjective point of view, even if we may be able to explain their choice by environment and instincts. But this is speculation because no animal will ever be able to tell us its feelings.
Photo credit: flickr.com/photos/brixton/404168521/