“The Temporal Pattern to the Experience of Regret”, 1994 (; backlinks):
Through telephone surveys, written questionnaires, and face-to-face interviews, it was found that people’s biggest regrets tend to involve things they have failed to do in their lives.
These divergent findings were reconciled by demonstrating that people’s regrets follow a systematic time course: actions cause more pain in the short-term, but inactions are regretted more in the long run.
Support for this contention was obtained in 2 scenario experiments that assessed people’s beliefs about the short-term & long-term regrets of others and in an experiment that asked Subjects about their own regrets of action and inaction from 2 time periods. A total of 275 Subjects participated in the experiments.
Several mechanisms that can account for this temporal pattern are discussed.