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).