Jonathan Schooler surveys research suggesting that belief in free will correlates with desirable personal traits:
Recently we found that a belief in free will is positively correlated with a host of positive attributes (including: self-control, life satisfaction, subjective happiness, mindfulness, and ambition) and negatively correlated with several less desirable traits (such as neuroticism and mind-wandering). Of course, we must be cautious in drawing causal inferences from correlational studies. Nevertheless, these findings are consistent with the view … that a belief in free will affords some positive benefits.
Given these various lines of research, it might be tempting to conclude that a belief in free will makes us better people. However, I think such a blanket conclusion is misguided for a number of reasons.
First, the strengths of the relationships between belief in free will and the assorted positive traits and behaviors reviewed above, though observed in various labs and typically statistically significant, are generally relatively modest. Indeed, some studies have failed to find these relationships at all.
Second, although the bulk of studies investigating the issue have found positive benefits of a belief in free will, there is also evidence that a disbelief in free will has its advantages. For example, a recent set of studies by Sharif and colleagues found that discouraging a belief in free will reduced people’s tendency to punish purely for the sake of vengeance.
Finally, and perhaps most importantly, those who have concluded that a belief in free will is misguided would reasonably cringe at the notion that people who believe in a convenient fiction are “better” than those who have faced up to the reality of the situation.
The Dish 