We conduct a series of experiments and document a robust behavioral pattern whereby people behave more morally in uncertain environments than degenerate deterministic ones. We show that this pattern is weakened when the moral implication of behavior is diminished or when uncertainty pertains to others rather than oneself. These findings are incompatible with standard models that respect dominance. We propose a mechanism based on the anxiety aspect of uncertain environments whereby people act morally as if their moral behavior can help deliver a better outcome. We further delve into the complexity aspect of uncertainty to arrive at a more comprehensive understanding of these findings.