“…In operant conditioning, also referred to as associative learning, an animal also learns to associate certain signals with the positive or negative consequences of their behavior. Operant conditioning has been studied for over a century (Skinner, 2012; Thorndike, 1898), and numerous studies have now contributed to a rich understanding of the environmental and biological factors that underlie animal learning across many species, including invertebrates (Hawkins & Byrne, 2015), birds (Park, Okanoya, & Dooling, 1985), fish (Lucon-Xiccato & Bisazza, 2016; Thompson & Sturm, 1965), and mammals (Grant, 1964), including monkeys (Alvarado, Malkova, & Bachevalier, 2016). …”