Meliorating the Suboptimal-Choice Argument

Abstract

Zentall's (2019) target article, "What suboptimal choice tells us about the control of behavior," is in three parts. The first part reviews a set of studies that have yielded surprising findings: In relatively simple choice tasks, animals seem to behave irrationally by making suboptimal choices. The second part introduces a set of hypotheses to account for the surprising findings: Animals may behave according to a variety of heuristics that are adaptive in their natural environments but maladaptive in the contrived laboratory settings. The third part explains what suboptimal choice in fact tells us about the control of behavior. In this commentary we argue that Part 1 is timely, interesting, and important; that Part 2, potentially the article's greatest contribution, includes imaginative, testable hypotheses alongside conceptually confused and even inconsistent hypotheses; and that Part 3 may be too vague to be useful. We conclude with some general remarks on the nature of the problems brought to our attention by the target article.

The Case for a Heuristic Approach to Account for Suboptimal Choice

“…We have suggested that some errors occur because the pigeons have difficulty remembering the previously chosen stimulus and, importantly, the consequence of that choice (Smith, Beckmann, & Zentall, 2017). But Carvalho et al (2019) question that account because the pigeons rarely make errors during many of the early and late trials in the session, so memory cannot be a factor on those trials. Of course, there is no need to remember the last chosen stimulus and the outcome of that choice early and late in the session because, after many sessions of training, the appropriate early and late choices would be well established in reference memory.…”

“…But it does not explain the results with pigeons involving two different kinds of grain, both intact (Zentall et al, 2014), or the finding with dogs involving a piece of carrot and piece of cheese (Pattison & Zentall, 2014), or even the results with monkeys involving a slice of cucumber and grape (Kralik, Xu, Knight, Khan, & Levine, 2012). Carvalho et al (2019) would also like an explanation for the individual differences. Given the fact that pigeons that showed the less is better effect were only minimally deprived of food, some of the individual differences may result from motivational differences.…”

“…Their commentary focuses on each of the phenomena covered in the target article (i.e., the less is better effect, the ephemeral reward effect, and the midsession reversal effect), and I respond to the critique of each phenomenon in turn. Carvalho et al (2019) note that consistent effects have not always been found. When inconsistent effects occur, they may be taken as the unreliability of the effect or they may define the boundary conditions of the phenomenon.…”

“…The strongest criticism of the target article comes from Carvalho, Santos, Soares, and Machado (2019). Their commentary focuses on each of the phenomena covered in the target article (i.e., the less is better effect, the ephemeral reward effect, and the midsession reversal effect), and I respond to the critique of each phenomenon in turn.…”

“…Certainly, I would concur that further research is needed to determine the conditions under which the less is better effect can be found. Carvalho et al (2019) question how impulsivity can account for the absence of an association between the first and second reinforcement by most primates, pigeons, and rats, and how the absence of impulsivity allows such associations to develop in wrasse and parrots. At a descriptive level, the animals that fail to choose optimally do not appear to base their choice on the events that follow the first reinforcement.…”