Development of Substitution Bias Sensitivity: Are Adolescents Happy Fools?

Development of Substitution Bias Sensitivity: Are Adolescents Happy Fools? Sandrine Rossi (sandrine.rossi@unicaen.fr) LaPsyDE (CNRS Unit 3521), University of Caen Basse-Normandie, Caen, France Mathieu Cassotti (mathieu.cassotti@parisdescartes.fr) LaPsyDE (CNRS Unit 3521), Paris Descartes University, Paris, France Marine Agogue (marine.agogue@mines-paristech.fr) Centre de Gestion Scientifique, Mines ParisTech, Paris, France Wim De Neys (wim.de-neys@parisdescartes.fr) CNRS, LaPsyDE (CNRS Unit 3521), Paris Descartes University, Paris, France Abstract Influential work on human thinking suggests that our judgment is often biased because we minimize cognitive effort and intuitively substitute hard questions by easier ones. Recent work with adults who solved the bat-and-ball problem, one of the most publicized examples of the substitution bias, suggests that people realize they are doing this and notice their mistake. In the present paper we look at the development of this substitution bias sensitivity. A group of young adolescents solved standard and isomorphic control versions of the bat-and-ball problem in which reasoners experience no intuitive pull to substitute. Adults have been shown to be less confident in their substituted, erroneous bat- and-ball answer than in their answer on the control version that does not give rise to the substitution. However, the present study established that this critical confidence drop was less pronounced for young adolescents. This implies that in contrast with adults, young adolescents do not yet fully acknowledge the questionable nature of their biased answer and remain more oblivious to the substitution. That is, young adolescent reasoners seem to behave more like happy fools who blindly answer erroneous questions without realizing it. Keywords: Decision-making; Bias; Development Introduction Human reasoners have been characterized as cognitive misers who show a strong tendency to rely on fast, intuitive processing rather than on more demanding, deliberate thinking (Evans, 2008; Kahneman, 2011). Although the fast and effortless nature of intuitive processing can sometimes be useful, it can also bias our reasoning. It has been argued that the key to this bias is a process of so-called attribute substitution – when people are confronted with a difficult question they often intuitively answer an easier one instead (e.g., Kahneman, 2011; Kahneman & Frederick, 2002). Consider the following example: A bat and a ball together cost $1.10. The bat costs $1 more than the ball. How much does the ball cost? When you try to answer this problem, the intuitive answer that immediately springs to mind is “10 cents”. Indeed, about 80% of university students who are asked to solve the “bat-and-ball” problem give the “10 cents” answer (e.g., Bourgeois-Gironde & Vanderhenst, 2009). But it is wrong. Obviously, if the ball were to cost 10 cents, the bat would cost $1.10 (i.e., $1 more) and then the total cost would be $1.20, rather than the required $1.10. The correct response is “5 cents”, of course (i.e., the bat costs $1.05). The explanation for the widespread “10 cents” bias in terms of attribute substitution is that people substitute the critical relational “more than” statement by a simpler absolute statement. That is, “the bat costs $1 more than the ball” is read as “the bat costs $1”. Hence, rather than working out the sum, people naturally parse $1.10, into $1 and 10 cents which is easier to do. In other words, because of the substitution people give the correct answer to the wrong question. The bat-and-ball problem is considered a paradigmatic example of people’s cognitive miserliness (e.g., Bourgeois- Gironde & Vanderhenst, 2009; Kahneman, 2011; Kahneman & Frederick, 2002; Toplak, West, & Stanovich, 2011). After all, the problem is really not that hard. Clearly, if people would reflect upon it for even a moment they would surely realize their error and notice that a 10 cents ball and a bat that costs a dollar more cannot total to $1.10. Hence, the problem with attribute substitution seems to be that people do typically not notice that they are substituting and do not realize their error (Kahneman & Frederick, 2005; Thompson, 2009; Toplak et al., 2011). This can sketch a somewhat bleak picture of human rationality: Not only do we often fail to reason correctly, much like happy fools, we do not even seem to realize that we are making a mistake. However, the fact that decision-makers do not deliberately reflect upon their response does not necessarily imply that they are not detecting the substitution process. That is, although people might not engage in deliberate processing and might not know what the correct answer is, it is still possible that they have some minimal substitution sensitivity and at least notice that their substituted “10 cents” response is not completely warranted (e.g., Alter, Oppenheimer, Epley, & Eyre, 2007; De Neys, 2012; De