How should the concept of evidence be understood? And how does the concept of evidence apply to the controversy about creationism as well as to work in evolutionary biology about natural selection and common ancestry? In this rich and wide-ranging book, Elliott Sober investigates general questions about probability and evidence and shows how the answers he develops to those questions apply to the specifics of evolutionary biology. Drawing on a set of fascinating examples, he analyzes whether claims about intelligent design (...) are untestable; whether they are discredited by the fact that many adaptations are imperfect; how evidence bears on whether present species trace back to common ancestors; how hypotheses about natural selection can be tested, and many other issues. His book will interest all readers who want to understand philosophical questions about evidence and evolution, as they arise both in Darwin's work and in contemporary biological research. (shrink)

Traditional analyses of the curve fitting problem maintain that the data do not indicate what form the fitted curve should take. Rather, this issue is said to be settled by prior probabilities, by simplicity, or by a background theory. In this paper, we describe a result due to Akaike [1973], which shows how the data can underwrite an inference concerning the curve's form based on an estimate of how predictively accurate it will be. We argue that this approach throws light (...) on the theoretical virtues of parsimoniousness, unification, and non ad hocness, on the dispute about Bayesianism, and on empiricism and scientific realism. * Both of us gratefully acknowledge support from the Graduate School at the University of Wisconsin-Madison, and NSF grant DIR-8822278 (M.F.) and NSF grant SBE-9212294 (E.S.). Special thanks go to A. W. F. Edwards.William Harper. Martin Leckey. Brian Skyrms, and especially Peter Turney for helpful comments on an earlier draft. (shrink)

This paper examines the recent literature on meta-cognitive processes in non-human animals, arguing that in each case the data admit of a simpler, purely first-order, explanation. The topics discussed include the alleged monitoring of states of certainty and uncertainty, knowledge-seeking behavior in conditions of uncertainty, and the capacity to know whether or not the information needed to solve some problem is stored in memory. The first-order explanations advanced all assume that beliefs and desires come in various different strengths, or degrees.

The question of whether chimpanzees, like humans, reason about unobservable mental states remains highly controversial. On one account, chimpanzees are seen as possessing a psychological system for social cognition that represents and reasons about behaviors alone. A competing account allows that the chimpanzee's social cognition system additionally construes the behaviors it represents in terms of mental states. Because the range of behaviors that each of the two systems can generate is not currently known, and because the latter system depends upon (...) the former, determining the presence of this latter system in chimpanzees is a far more difficult task than has been assumed. We call for recognition of this problem, and a shift from experimental paradigms that cannot resolve this question, to ones that might allow researchers to intelligently determine when it is necessary to postulate the presence of a system which reasons about both behavior and mental states. (shrink)

This paper examines the recent literature on meta-cognitive processes in non-human animals, arguing that in each case the data admit of a simpler, purely first-order, explanation. The topics discussed include the alleged monitoring of states of certainty and uncertainty, the capacity to know whether or not one has perceived something, and the capacity to know whether or not the information needed to solve some problem is stored in memory. The first-order explanations advanced all assume that beliefs and desires come in (...) various different _strengths_, or _degrees_. (shrink)

Akaike's framework for thinking about model selection in terms of the goal of predictive accuracy and his criterion for model selection have important philosophical implications. Scientists often test models whose truth values they already know, and they often decline to reject models that they know full well are false. Instrumentalism helps explain this pervasive feature of scientific practice, and Akaike's framework helps provide instrumentalism with the epistemology it needs. Akaike's criterion for model selection also throws light on the role of (...) parsimony considerations in hypothesis evaluation. I explain the basic ideas behind Akaike's framework and criterion; several biological examples, including the use of maximum likelihood methods in phylogenetic inference, are considered. (shrink)

Akaike’s framework for thinking about model selection in terms of the goal of predictive accuracy and his criterion for model selection have important philosophical implications. Scientists often test models whose truth values they already know, and they often decline to reject models that they know full well are false. Instrumentalism helps explain this pervasive feature of scientific practice, and Akaike’s framework helps provide instrumentalism with the epistemology it needs. Akaike’s criterion for model selection also throws light on the role of (...) parsimony considerations in hypothesis evaluation. I explain the basic ideas behind Akaike’s framework and criterion; several biological examples, including the use of maximum likelihood methods in phylogenetic inference, are considered. (shrink)

The chapter discusses the principle of conservatism and traces how the general principle is related to the specific one. This tracing suggests that the principle of conservatism needs to be refined. Connecting the principle in cognitive science to more general questions about scientific inference also allows us to revisit the question of realism versus instrumentalism. The framework deployed in model selection theory is very general; it is not specific to the subject matter of science. The chapter outlines some non-Bayesian ideas (...) that have been developed in model selection theory. The principle of conservatism, like C. Lloyd Morgan's canon, describes a preference concerning kinds of parameters. It says that a model that postulates only lower-level intentionality is preferable to one that postulates higher-level intentionality if both fit the data equally well. The model selection approach to parsimony helps explain why unification is a theoretical virtue. (shrink)

An empirical procedure is suggested for testing a model that postulates variables that intervene between observed causes and abserved effects against a model that includes no such postulate. The procedure is applied to two experiments in psychology. One involves a conditioning regimen that leads to response generalization; the other concerns the question of whether chimpanzees have a theory of mind.

There is a persistent methodological problem in primate mindreading research, dubbed the 'logical problem,' over how to determine experimentally whether chimpanzees are mindreaders or just clever behavior-readers of a certain sort. The problem has persisted long enough that some researchers have concluded that it is intractable. The logical problem, I argue, is tractable but only with experimental protocols that are fundamentally different from those that have been currently used or suggested. In the first section, I describe what the logical problem (...) is and how it can, in principle, be solved. In the second section, I illustrate how a well-known experimental protocol by Hare et al. fails to solve the logical problem. In the third section, I do the same for a protocol by Heyes . .) In the fourth section, I describe a novel experimental protocol for visual perspective-taking and argue that it succeeds to discriminate between the relevant mindreading and behavior-reading hypotheses. In addition, this new experimental protocol employs procedures that are realistic enough to suppose that chimpanzees might very well succeed in passing them. (shrink)

In this paper, I'll explore three contexts in which the heuristic of personification yields the wrong answer. They all come from game theoretic discussion of altruism and the Prisoner's Dilemma. Whether it is applied to evolution or to rational deliberation, game theory models situations that involve frequency dependence. In the evolutionary case, how fit a trait is, and whether it is more or less fit than the alternatives, depends on the composition of the population (Maynard Smith 1982). In the case (...) of rational deliberation, which act is best for the agent depends on what other actors are likely to do. As we now will see, frequency dependence can throw a monkey wrench into the convenient relationship between deliberation and evolution posited by the heuristic of personification. (shrink)