“…Our findings confirm and extend previous results from behavioral studies showing that reinforcement contingencies can control the variability of response sequences (for reviews, see Lee et al, 2007;Neuringer, 2002Neuringer, , 2009. Indeed, various levels of variability in sequences of keys pecks and levers presses have been reinforced in animals (e.g., Machado, 1989Machado, , 1992Page & Neuringer, 1985) as well as in manual response sequences in humans (e.g., Hopkinson & Neuringer, 2003;Lee, McComas, & Jawor, 2002;Neuringer, 1986;Neuringer & Voss, 1993;Souza, Pontes, & AbreuRodrigues, 2012).…”