The Evolution of Misbelief
Abstract (Via Tufts)
From an evolutionary standpoint, a default presumption is that true beliefs are adaptive and misbeliefs maladaptive. But if humans are biologically engineered to appraise the world accurately and to form true beliefs, how are we to explain the routine exceptions to this rule? How can we account for mistaken beliefs, bizarre delusions, and instances of self-deception? We explore this question in some detail. We begin by articulating a distinction between two general types of misbelief: those resulting from a breakdown in the normal functioning of the belief formation system (e.g., delusions) and those arising in the normal course of that system’s operations (e.g., beliefs based on incomplete or inaccurate information). The former are instances of biological dysfunction or pathology, reflecting “culpable” limitations of evolutionary design. Although the latter category includes undesirable (but tolerable) by-products of “forgivably” limited design, our quarry is a contentious subclass of this category: misbeliefs best conceived as design features. Such misbeliefs, unlike occasional lucky falsehoods, would have been systematically adaptive in the evolutionary past. Such misbeliefs, furthermore, would not be reducible to judicious – but doxastically1 noncommittal – action policies. Finally, such misbeliefs would have been adaptive in themselves, constituting more than mere by-products of adaptively biased misbeliefproducing systems. We explore a range of potential candidates for evolved misbelief, and conclude that, of those surveyed, only positive illusions meet our criteria.
Introduction (Via Tufts)
A misbelief is simply a false belief, or at least a belief that is not correct in all particulars. We can see this metaphorically: If truth is a kind of target that we launch our beliefs at, then misbeliefs are to some extent wide of the mark. Of course, there is no philosophical consensus about just what a belief actually is. In what follows we intend to avoid this question, but we offer here the following working definition of belief, general enough to cover most representationalist and dispositional accounts: A belief is a functional state of an organism that implements or embodies that organism’s endorsement of a particular state of affairs as actual.2 A misbelief, then, is a belief that to some degree departs from actuality – that is, it is a functional state endorsing a particular state of affairs that happens not to obtain.
A prevailing assumption is that beliefs that maximise the survival of the believer will be those that best approximate reality (Dennett 1971; 1987; Fodor 1983; 1986; Millikan 1984a; 1984b; 1993). Humans are thus assumed to have been biologically engineered to form true beliefs – by evolution. On this assumption, our beliefs about the world are essentially tools that enable us to act effectively in the world. Moreover, to be reliable, such tools must be produced in us, it is assumed, by systems designed (by evolution) to be truth-aiming, and hence (barring miracles) these systems must be designed to generate grounded beliefs (a system for generating ungrounded but mostly true beliefs would be an oracle, as impossible as a perpetual motion machine). Grounded beliefs are simply beliefs that are appropriately founded on evidence and existing beliefs; Bayes’ theorem (Bayes 1763) specifies the optimal procedure for revising prior beliefs in the light of new evidence (assuming that veridical belief is the goal, and given unlimited time and computational resources; see Gigerenzer & Goldstein 1996). Of course, just as we can have good grounds for believing propositions that turn out to be false, so can ungrounded beliefs be serendipitously true (others arguably lack truth values). To keep our exposition manageable, we will not consider such ungrounded beliefs to be misbeliefs, although we acknowledge that false and (serendipitously) true ungrounded beliefs (and perhaps those lacking truth values) may well be produced in much the same way – and by much the same types of mechanism (we return to this issue in sect. 14).
If evolution has designed us to appraise the world accurately and to form true beliefs, how are we to account for the routine exceptions to this rule – instances of misbelief? Most of us at times believe propositions that end up being disproved; many of us produce beliefs that others consider obviously false to begin with; and some of us form beliefs that are not just manifestly but bizarrely false. How can this be? Are all these misbeliefs just accidents, instances of pathology or breakdown, or at best undesirable (but tolerable) by-products? Might some of them, contra the default presumption, be adaptive in and of themselves?