State-Dependent Decisions Cause Apparent Violations of Rationality in Animal Choice

Normative models of choice in economics and biology usually expect preferences to be consistent across contexts, or “rational” in economic language. Following a large body of literature reporting economically irrational behaviour in humans, breaches of rationality by animals have also been recently described. If proven systematic, these findings would challenge long-standing biological approaches to behavioural theorising, and suggest that cognitive processes similar to those claimed to cause irrationality in humans can also hinder optimality approaches to modelling animal preferences. Critical differences between human and animal experiments have not, however, been sufficiently acknowledged. While humans can be instructed conceptually about the choice problem, animals need to be trained by repeated exposure to all contingencies. This exposure often leads to differences in state between treatments, hence changing choices while preserving rationality. We report experiments with European starlings demonstrating that apparent breaches of rationality can result from state-dependence. We show that adding an inferior alternative to a choice set (a “decoy”) affects choices, an effect previously interpreted as indicating irrationality. However, these effects appear and disappear depending on whether state differences between choice contexts are present or not. These results open the possibility that some expressions of maladaptive behaviour are due to oversights in the migration of ideas between economics and biology, and suggest that key differences between human and nonhuman research must be recognised if ideas are to safely travel between these fields

Ecological rationality - Intelligence in the world

The idea that more information and more computation yield better decisions has long shaped our vision of rationality. Yet humans and other animals typically rely on simple heuristics or rules of thumb to solve adaptive problems, focusing on one or a few important cues and ignoring the rest, and shortcutting computation rather than striving for as much as possible. In this book, the authors argue that in an uncertain world, more information and computation are not always better, and instead ask when, and why, less can be more. The answers to these questions constitute the idea of ecological rationality, as explored in the chapters in this book: how people can be effective decision makers by using simple heuristics that fit well to the structure of their environment. When people wield the right tool from the mind's adaptive toolbox for a particular situation, they can make good choices with little information or computation-enabling simple strategies to excel by exploiting the reliable patterns in the world to do some of the work. Heuristics are not good or bad, "biased" or "unbiased," on their own, but only in relation to the setting in which they are used. The authors show heuristics and environments fitting together to produce good decisions in domains including sports competitions, the search for a parking space, business group meetings, and doctor/patient interactions. The message of Ecological Rationality is to study mind and environment in tandem. Intelligence is not only in the mind but also in the world, captured in the structures of information inherent in our physical, biological, social, and cultural surroundings

Simple Heuristics in a Social World

This book invites readers to discover the simple heuristics that people use to navigate the complexities and surprises of environments populated with others. The social world is a terrain where humans and other animals compete with conspecifics for myriad resources, including food, mates, and status, and where rivals grant the decision maker little time for deep thought, protracted information search, or complex calculations. The social world also encompasses domains, however, where social animals such as humans learn from one another how to deal with the vagaries of a natural world that both inflicts unforeseeable hazards and presents useful opportunities and dare to trust and forge alliances with one another to boost their chances of success. According to the book's thesis, the undeniable complexity of the social world does not dictate cognitive complexity as many scholars of rationality argue. Rather, it entails circumstances that render optimization impossible or computationally arduous: intractability, the existence of incommensurable considerations, and competing goals. With optimization beyond reach, less can be more. That is, heuristics-simple strategies for making decisions when time is pressing and careful deliberation an unaffordable luxury-become indispensible mental tools. As accurate or even more accurate than complex methods when used in the appropriate environments, these heuristics are good descriptive models of how people make many decisions and inferences, but their impressive performance also poses a normative challenge for optimization models. In short, the homo socialis may prove to be a homo heuristicus whose intelligence reflects ecological rather than logical rationality