Unfortunately, the human capac-
ity to exert cognitive control over goal-incongruent
impulses is far from perfect (Carlson, Zelazo, & Faja,
2013; Cohen, 2005; Diamond, 2013). For instance, adults
make mistakes on simple tasks of executive function,
which require exercising top-down control over conflict-
ing subcortical impulses. For instance, the classic Stroop
task takes advantage of the fact that reading is a relatively
automatic response for mature adults (Stroop, 1935). In
this task, individuals try to state aloud the color of the ink
in which a contrasting color word is printed (e.g., saying
the word “blue” when presented with the word “red”
written in blue ink). Even when successful, exercising
executive function is reliably effortful and, in most cases,
at least mildly aversive (Inzlicht, Legault, & Teper, 2014;
Kurzban et al., 2013; Westbrook & Braver, 2015). Similarly,
hiding our emotions (e.g., trying not to cry when sad or
trying not to smile when amused) sometimes works but
often does not and, even when successful, takes a physi-
ological toll (Gross & Levenson, 1993).
