These data stem from five large studies examining the relation between episodic future thinking and delay of gratification in preschoolers, children, and adolescents. Study 1 examined the relation between episodic future thinking and performance on a delay choice task in preschoolers; Study 2 examined whether performance in preschoolers on delay choice was enhanced by encouraging participants to thinking episodically about the future. The results of Studies 1 and 2 indicate that while there may be some relations between delay choice and episodic future thinking in this age group, children this age do not benefit from being primed to think episodically. Studies 3 and 4 examined similar issues in older children. The findings of Study 3 indicated that episodic future thinking is not related to delay choice in this age group, but that a measure of subjective future time was predictive, suggesting that how children represent the distance in time of future events has an impact on whether they decide to delay gratification. Study 4 found that older children, like preschoolers, do not benefit from being primed to think episodically about the future. Study 5 examined such priming in adolescents and adults, and included a novel priming condition in which participants thought about future episodes concerning another person. The findings demonstrated the standard episodic future priming effect in both adolescents and adults but there was no benefit in the novel priming condition. These results suggest that episodic future priming is not beneficial to delay of gratification until the adolescent years, and that such priming must specifically involve thought about the future self.We are often faced with a choice between doing something that has an immediate reward (e.g., spending money on a treat) and doing something that has no immediate benefit but is in the longer-term more advantageous (e.g., saving to buy a house). Choosing the smaller immediate reward over the larger, future reward has been described as "discounting" the larger future reward (i.e., the value of the delayed reward is seen as lower because of how far away in time it is). Such discounting has been extensively studied by psychologists, not least because the choices people make in experiments are predictive of various sorts of potentially harmful real-world behavior (e.g., overeating, gambling, substance abuse). Psychologists are particularly interested in finding out which psychological processes may reduce discounting because this can help them develop appropriate interventions. It has been claimed that a particular sort of thought about the future plays a special role in supporting prudent decision making: what is termed episodic future thinking (EFT). EFT involves imagining in one's mind's eye specific events in one's own future, i.e., mentally "pre-experiencing" events before they happen. Indeed, studies with adults have suggested that encouraging people to think episodically about the future can help reduce discounting, with these findings beginning to form the basis of some novel interventions. Young children have difficulty making prudent choices. The tendency to discount future rewards decreases gradually across childhood and also changes over adolescence, with 16-year-olds being more likely to make prudent choices than 14-year-olds. However, as yet, we do not fully understand the developmental changes that lie behind these important improvements in future-oriented decision making. EFT skills first emerge around 4 to 5 years, and, like future-oriented decision making, EFT continues to improve into adolescence. However, nothing is currently known about how the development of EFT and the development of decision making are linked. This project will examine this issue for the first time in a series of experiments that explore whether children's and adolescents' EFT abilities are linked to their tendency to discount future rewards. We will also test whether encouraging children and adolescents to think episodically about the future enhances their decision making, by contrasting the effects of EFT versus other sorts of thinking on discounting behavior. Finally, the project will examine a further untested hypothesis regarding developmental changes in future-oriented decision making: that younger children are more likely to discount future rewards because times in the future feel farther away to them than to older children. Existing research suggests that adults may differ in their tendency to discount future rewards in part because of differences in how far away the distant future feels to them. However, we do not know if this can explain age differences. We will thus examine whether any developmental differences in how far away the future feels are linked to EFT skills and, more specifically, the idea that difficulties younger children have in imagining events in their futures means that future rewards seem very distant in time. This project will not only shed light on important developmental changes in decision making, it will also help psychologists understand the processes underlying prudent choice and the function of EFT. Such understanding is crucial for developing interventions to enhance future-oriented decision making in children, adolescents, and adults.

This project involved a series of five experimental studies. In Studies 1-4, participants were recruited through nursery and primary schools local to the PI's institution in Northern Ireland. The schools sent letters to parents in advance of testing, and only children whose parents consented in writing to their child's participants were included in the studies. Children were asked to provide assent. The population of children was primary drawn from lower to middle class socio-economic status, and were primarily of White ethnic background reflecting the demographics of the local population in Northern Ireland. Testing was conducted individually with each child in nurseries and primary schools by administering a set of experimental tasks. These tasks are described in detail in the Summary file associated with each study. Study 5 was conducted with adolescents and adults. Adolescents were recruited through secondary schools local to the PI's institution. Schools distributed letters to parents and only children whose parents had given written consent were included in the study. Adolescents were also asked to give written consent. The demographics of the adolescent and adult population were similar to that in Studies 1-4. Testing of adolescents was conducted in groups in their schools, and the tasks were experimental tasks that were completed online on school computers. Adults were recruited through Queen's University Belfast and were recruited through email and poster advertisement in the university and provided written consent. Adults were tested either individually or in groups in a research lab using the same set of online tasks that had been administered to adolescents. A detailed description of the experimental tasks is given in the Summary document for Study 5.