BETWEEN FORMAL LOGIC AND NATURAL LOGIC

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based on natural logic—called heuristics—character- ... mal calculus, the heuristic evaluation of probability is .... One example is the scarcity heuristic, which.
limited but still potent decision-making strategies. With his sweeping command of the many diverse disciplines that make up the whole intellectual enterprise, he asks us—nudges us, prods us—to ponder these nuances about our humanity with fresh eyes. Wray Herbert 1840 Columbia Road NW, #402 Washington, DC 20009 E-mail: [email protected]

Between Formal Logic and Natural Logic: Prolegomena for a Middle Way On Second Thought: Outsmarting Your Mind’s Hard-Wired Habits By Wray Herbert. New York, NY: Broadway Paperbacks, 2011. 304 pp. Paper, $15.

For more than 2,000 years we have believed that rationality, and logic in particular, guides our thoughts, establishes relationships between ideas, informs our judgments, and distinguishes truth from falsehood, right from wrong, even to the point of giving us control over our destiny. Indeed, this is one of the foundation myths of Western civilization. But is it really so? Are our lives actually informed by rationality? Over the last few decades a lot of theoretical and empirical research into decision making has demonstrated that our decisions, whether wise or absurd, originate in the basement of our brain and are only later promoted to the “upper floors” of consciousness. Our decision-making brain does not build up an ever greater stock of information but bases its choices on strategies that operate at a minimal level of awareness, in a shadow zone that is not structured according to the rigidly deductive laws of classical logic. Not only are these laws rigid, but they take a long time to apply. At least three factors make the time scale of rationality and formal logic extremely complex. In the first place, our mind has only a limited capacity to identify and elaborate information; in the second place, our cognitive processes are slow, and we cannot store all that much in our memory; and in the third place, the real world is an ambiguous and chaotic place that does not lend itself easily to being processed by logic-based inferences. The decision-making problems we grapple with day after day comprise intricate features (limitations of time, too much information, or too little) to which

we respond automatically using adaptive mechanisms based on natural logic—called heuristics—characterized by rapidity and frugality (Gigerenzer, 1997). These often are the only cognitive procedures available to us for evaluating elements of uncertainty. Unlike formal calculus, the heuristic evaluation of probability is based on immediate solutions that take into account only some of the factors at stake: the peculiarity of the object being evaluated, the way in which the problem is formulated, the clarity with which the situation is described, and so on. These factors have been subjected to extensive experimental analysis by cognitive scientists, showing how the various heuristics exert an influence, whether separately or in conjunction, on decision-making behavior. Thus the concept of heuristics has acquired an experimental validity, challenging thinkers to come up with a more realistic model for a rational agent and for the concept of rationality itself. Thanks to the classic experiments of Kahneman and Tversky (1973), it is now possible to recognize that the choices made by decision makers are by no means optimal and to investigate the limitations governing the elaboration and calculation of information. Such limitations encourage recourse to adaptive strategies: The framing effect and prospect theory in particular reflect the interference of cognitive and context-based elements when it comes to evaluating a problem and the available information. In fact, we can make diametrically opposed decisions with respect to a problem according to how our mind represents the problem or how the problem is presented to us, because the presentation may be biased. This explains why we are so easily influenced by publicity and behave so irrationally. Marketing experts know perfectly well that when shopping in a supermarket, for example, we do not act to maximize utility; shoppers’ behavior is guided much more by the way goods are displayed than by their inherent quality. In such a case, carefully considered and coherent behavior counts for little because our choices actually depend on much more wide-ranging and variegated processes than the degrees of efficiency postulated by normative theories. In situations of risk and uncertainty, we hardly ever evaluate alternative choices in absolute terms but rather in relation to a subjective paradigm. In fact, the same quantity may be considered as desirable if it is viewed as a gain and undesirable when viewed as a loss. To our minds, data, percentages, and statistics are not objective, and we are often taken in by false impressions. Like their visual counterparts, cognitive

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illusions are induced by automatic processes favoring a rapid and intuitive decoding of reality, even if this proves approximate and misleading (Hamilton & Gifford, 1976; Nisbett & Ross, 1980). How then are we to consider these strategies and their role in decision making? On Second Thought, by Wray Herbert, is a fascinating journey into the world of (mostly unconscious) cognitive shortcuts that since the dawn of time have enabled human beings to respond promptly to adaptive challenges. It introduces us into a mysterious universe, throwing light onto some significant shadow zones concerning these phenomena. Herbert shows how reflex responses not only have nothing to do with formal logic but actually originate in the quicksands of uncertainty, intuition, emotions, and other shady impulses. He makes it clear that most human decisions have always been based on a natural logic whose rules, though undoubtedly fallible and less rigorous, have favored evolution. This logic, in which heuristics play a fundamental part, has been consolidated in the course of evolution and in all probability can be traced back to the era when human beings existed in a hostile environment (Maldonato & Dell’Orco, 2011). Our ancestors had to be quick at finding an escape route or reacting to the aggression of a predator, quick at deciding whether to follow prey, quick at conquering a territory or choosing a dwelling place. Although nowadays the environmental pressures are less acute than they once were, our daily choices are often guided by heuristic processes. However, although these processes make for economy in decision-making processes and exempt us from the infinite calculations that would make rigorous reasoning totally impractical, precisely because they are rapid and simplistic, they are often the cause of blunders, causing us to make systematic failures. Using reallife examples and an admirably clear, informal style, Herbert invites us to pay attention to the traps and errors we fall into when we evaluate the probabilities and risks associated with our decisions, the illusions that make it difficult to foresee the consequences of our choices, the ways in which our emotions influence our perceptions, and more besides. Although in some decisions—at the supermarket, for example—heuristics can undoubtedly be of help, for others, above all in the sphere of interpersonal relationships such as the choice of a partner or of someone to trust, we need to give closer consideration to the various elements at stake. Failure to do so will mean that we risk misjudging others and mak-

ing decisions on the basis of prejudices or distorted information. Herbert begins by introducing a class of heuristics that are fundamental in enabling humans to adapt to their environment. They concern the way in which our body constantly interacts with the world around us. Among these is the visceral heuristic, which evolved together with one of the primary human necessities: to reproduce and ensure the survival of offspring and hence of the species. Throughout evolution humans have always made unconscious evaluations of potential partners, favoring those who appear to offer the greatest chances of reproduction. Focus on characteristics such as youthfulness or a healthy, well-groomed appearance—indications of fertility and hence of evolutionary advantage (Buss, 2005; Huang & Bargh, 2008)—can lead us to ignore other features that are no less (or indeed possibly more) important, such as character and shared interests. This bias can have serious consequences on a relationship and on offspring. Another fundamental class of heuristics are the cognitive strategies that, day in day out, on the basis of the information available in the world around us, allow us to perform automatic mental calculations. One example is the scarcity heuristic, which underpins the belief that if a certain commodity is in short supply, then it must be valuable. Numerous experiments (Myrseth, Fishbach, & Trope, 2009) have borne out this general tendency. When a product or commodity becomes readily available, people tend to consider it less valuable and hence less desirable, whereas when the same product is not readily available, it is seen as more precious and desirable. Dieting is a case in point. Who cannot recall having no particular wish for a certain food until going on a diet in which that food was prohibited? Even though the prohibition was self-imposed, once that food was out of bounds it suddenly became highly desirable. Herbert suggests that this heuristic developed out of the evolutionary necessity to stockpile resources that are not easily available but essential for survival. No less important is the class of heuristics described in the last section of the book: the unconscious strategies whereby we try to attribute a sense to the world and the people we encounter every day of our lives. In the course of time we acquire not only experience but also a substantial stock of stereotypes. In some cases, above all in situations of cognitive overload or in the presence of drastic environmental limitations (when, for example, there is not

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enough time to evaluate all the available information), we unconsciously fall back on stereotypes to form an immediate judgment. This tendency has been confirmed by a number of experiments (Bodenhausen, 1990, 2005) showing how—above all when we are not really concentrating—we judge others according to type. This has important implications in the legal context, for instance. Contrary to what one would expect, the choices made are not always the most judicious, even in the case of a judge or jury. Experimental investigations have shown that members of a jury who are asked to come to a decision at a time of day when they are tired and less able to concentrate have greater difficulty in reaching an objective decision and are more likely to fall back on stereotypes in passing judgment. Naturally such oversights and errors of judgment may have serious consequences. In recent decades the waning of the paradigm of perfect rationality has allowed us to begin conceiving of an imperfect, problematic, and indeed self-critical rationality. There has been an exponential growth in experiments investigating the crucial role of heuristics and subcortical processes informing our day-today decisions, showing that making errors in choices and reasoning is part and parcel of the human mind, constituting a sort of “rational ignorance” (Downs, 1957). Not only do humans not possess the computational resources to carry out the calculations of probability required by the theory of rational choice, but they deploy their rationality in contexts with which they are only partially familiar and by which they are constantly influenced. However, it would be a mistake to ignore the biases to which we often succumb when we rely wholly on heuristics and ignore the other variables involved. In some cases we find (too late, unfortunately) that we needed only to think about something for a few seconds more in order to make a better choice and avoid errors. It is all a matter of recognizing when we can trust our instinct and when it would be wiser to stop and reflect more deeply before taking a decision. Herbert’s book is important for two reasons. In the first place, it will satisfy many people’s curiosity about the sometimes bizarre ways in which heuristics guide our day-to-day decision making, and then it represents an original manual for learning to recognize, and perhaps also to rectify, the mistakes we make when we trust entirely in that little homunculus (whether we refer to it as heuristic, intuition, instinct,

or whatever) that jumps up and down inside our head and does not allow us due time to reflect. We should pursue a third way between formal logic and natural logic, in which our decisions become the outcome of a conscious negotiation between the rational and the irrational, between affectivity and cognition, in a co-implication in which the former provides reinforcement of the latter and vice versa. Mauro Maldonato Department of Historical, Linguistic, and Anthropological Sciences University of Basilicata Via N. Sauro 85 85100 Potenza E-mail: [email protected] References

Bodenhausen, G. V. (1990). Stereotypes as judgmental heuristics: Evidence of circadian variations in discrimination. Psychological Science, 1, 319–322. Bodenhausen, G. V. (2005). The role of stereotypes in decision-making processes. Medical Decision Making, 25, 112–118. Buss, D. (2005). The handbook of evolutionary psychology. Hoboken, NY: Wiley. Downs, A. (1957). An economic theory of democracy. New York, NY: Harper & Row. Gigerenzer, G. (1997). Bounded rationality: Models of fast and frugal inference. Berlin, Germany: Max Planck Institute for Human Development. Hamilton, D. L., & Gifford, R. K. (1976). Illusory correlation in interpersonal perception: A cognitive basis of stereotypic judgments. Journal of Experimental Social Psychology, 12(4), 136–149. Huang, J. Y., & Bargh, J. A. (2008). Peak of desire: Activating the mating goal changes life-stage preferences across living kinds. Psychological Science, 19, 573–578. Kahneman, D., & Tversky, A. (1973). On the psychology of prediction. Psychological Review, 80(4), 237–251. Maldonato, M., & Dell’Orco, S. (2011). Natural logic: Exploring decision and intuition. Brighton, England: Sussex Academic Press. Myrseth, K. O. R., Fishbach, A., & Trope, Y. (2009). Counteractive self-control: When making temptation available makes temptation less tempting. Psychological Science, 20, 159–163. Nisbett, R. E., & Ross, L. (1980). Human inference: Strategies and shortcomings of social judgment. Englewood Cliffs, NJ: Prentice Hall.

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