The Effect of Symbolic Distancing on Delay Tolerance across the Preschool Period

Delayed gratification: A grey parrot (Psittacus erithacus) will wait for more tokens.

“…One criticism of the use of such tasks in testing the ability to wait is that the subjects, just as in the RRC task, may not be able to inhibit choosing the larger food quantity—that is, do not actually factor wait-time into the choice, so that their choice of larger-later is skewed by hedonic input. Notably, capuchin monkeys chose larger-later reward more often when food rewards were presented than when symbolic cues designating different quantities were presented, and young (∼3–4 years old) human children behaved similarly (Addessi et al, 2014; although less so when ∼6 years old—see Pecora et al, 2020). Sato et al (2021) found that some but not all chimpanzees, when tested with tokens and postreward delays that did or did not equalize intertrial intervals (ITIs), adapted their larger-later/smaller-sooner choices to maximize overall reward intake (i.e., with short ITIs, many smaller-sooner choices can maximize reward over one larger-later; if a postreward delay equalizes the number of trials in a time period, the larger-later would maximize reward).…”

Computerized intertemporal choice task in chimpanzees (Pan troglodytes) with/without postreward delay.

“…Capuchin monkeys chose larger-later rewards more often when food rewards were presented than when low- or high-symbolic cues were presented. Human children also chose larger-later rewards more often when food rewards were presented than when high-symbolic cues were presented, although this difference was no longer observed when some of the same children were tested again ∼2 years later (Pecora et al, 2020). Similarly, Labuschagne et al (2017) suggested that 4-year-old human children seemed to choose larger-later rewards more often when rewards (stickers) were indicated by photographs of stickers than when rewards were indicated by symbolic cues depending on the amount of rewards (but note that Evans et al [2012] reported a negligible or even an opposite effect of using symbols in accumulation tasks with chimpanzees and capuchin monkeys).…”