This data set is comprised of six folders containing eight data files each of which contains data from an experiment (or set of experiments) designed to investigate the role played by children's ability to experience and anticipate regret in their decision making. In each experiment, participants (usually children) were tested individually by an experimenter. Our research protocols required them to complete tasks measuring their ability to experience regret (and sometimes to anticipate it) and simple decision making tasks. In a small number of the experiments we also controlled for cognitive ability by collecting data on a standardised measure.Regret has been argued to play an important role in decision making. By studying how children’s choices are affected by bad outcomes, this project proposes a new way of determining whether regret facilitates profitable decision making. It is known that at six years of age only some children are capable of experiencing regret. There is also some evidence that the ability to experience regret is associated with the tendency to choose profitably in response to earlier bad outcomes. This project will explore whether the relationship between regret and decision making is a causal one, and whether good decision making depends on the ability to experience regret over a specific outcome, or the more general ability to anticipate regret. Finally, the project will examine whether the experience or anticipation of regret plays an important role in the ability to delay gratification, and in children’s decision making under conditions of risk. An associated postgraduate student will examine several of the same issues using adapted versions of the developmental tasks with patients who have difficulties experiencing or anticipating regret due to brain damage. These complementary lines of research will help to clarify the relationship(s) between regret and decision making.

Data was collected individually by an experimenter usually in a quiet location at the participant's school. The experimenter recorded the participants' responses and subsequently computer-entered them. In one experiment we recruited a sample of adolescents and adults. These participants were tested in a laboratory at Queen's University Belfast. The details of five out of eight of the experiments have been published and a copy of the article is provided in each case so that interested researchers can access information about the methods used. For each of the three experiments which are currently under review, we have provided a brief methods sections to help researchers interpret the data files.