Deception and truth detection when analyzing nonverbal and verbal cues

In this article, I present my view on the significant developments and theoretical/empirical tipping points in nonverbal and verbal deception and lie detection from the last 30 years and on prospects for future research in this domain. I discuss three major shifts in deception detection research: (a) From observing target persons' nonverbal behavior to analyzing their speech; (b) from lie detection based on differences between truth tellers and liars' levels of arousal to lie detection based on the different cognitive processes or strategies adopted to appear convincing; and (c) from passively observing target persons to actively interviewing them to elicit or enhance verbal cues to deceit. Finally, I discuss my ideas for future research, focusing on initiatives from my own lab. Hopefully, this will stimulate other researchers to explore innovative ideas in the verbal deception research domain, which already has seen so much progress in the last decade.     

Paradigms and possibilities

This paper is a excursus into a philosophy of science for deployment in the study of sport. It argues for the virtues of Thomas Kuhn's account of the philosophy of science, an argument conducted strategically by contrasting that account with one derived from views of Karl Popper. In particular, it stresses, first, that Kuhn's views have been widely misunderstood; second, that a rectified Kuhnianism can give due weight to truth in science, while recognising that social sciences differ in crucial ways from natural sciences. For, as Kuhn recognised, social sciences do not function in the paradigm-relative way characteristic of natural sciences. Yet there Kuhn's jargon, and especially misguided talk of ‘paradigms’, is almost ubiquitous.

These thoughts have relevance for three groups. First, as both sports scientists and exercise scientists come to grips with the claims to scientificity of their work, they will need increasingly to locate it within an epistemological framework provided by philosophy of science. So they must begin to take Kuhn's view seriously. Second, social scientists of sport – faced with the predominant scientism of colleagues in sport and exercise science – must also recognise alternatives to a postmodernist rejection of the concept of truth, where Kuhn's picture of natural science clarifies one such. Finally, philosophers writing on sport must not let antipathy to scientism close off the options they present or the terms in which they (we!) present them. And that may require debate among ourselves on abstract issues not immediately connected with sport.     

Vacuous truth

Special thanks go to Paul Humphreys for his criticisms and helpful comments. Also Richard Gale, Gerald Massey, Nicholas Rescher, David Blumenfeld, James Humber, Richard Ketchum, and Wolfgang Dietel made helpful comments on an earlier version. Each found something in need of repair. Finally, I would like to thank the Hambidge Center and the Center for the Philosophy of Science at the University of Pittsburgh for providing in 1988 the setting and the resources that made this paper possible.     

Approximate truth

Conclusion The technical results presented here on continuity and approximate implication are obviously incomplete. In particular, a syntactic characterization of approximate implication is highly desirable. Nevertheless, I believe the results above do show that the theory has considerable promise for application to the areas mentioned at the top of the paper.Formulation and defense of realist interpretations of science, for example, require approximate truth because we hardly ever have evidence that a particular scientific theory corresponds perfectly with a portion of the real world. Realists need to assert, then, that evidence for a theory is evidence for its approximate truth, not its truth (see [3] and [18]). Approximate truth is, however, a vague notion, and specification of quantity terms and of a sense of approximation are needed to make precise applications of it. Suitability of both vocabulary and sense of approximation depend on the subject matter, and their selection is a partly empirical matter that raises complex issues. In light of the number of common inferences which are not continuous, realists also need to be concerned about indiscriminate use of deductive logic to derive consequences from approximately true theories. These issues will be considered further in a future paper.Approximate truth also has potential application in areas of artificial intelligence that require inference from inaccurate data. In the qualitative physical theories of de Kleer and Brown [6], for example, qualitative values are derived by partitioning the real numbers into regions. Inferences leading from inside to outside a region must be identified and avoided, and approximate implication and continuity may prove useful in doing this. More generally, growing use of predicate logic as a programming language invites application of the theory of approximate truth as a symbolic substitute for numerical evaluation of computation errors. This too will be the subject of a future paper.Thanks to R. Boyd, A. Garfinkel, H. Hertz, P. Solomon, P. Suppes, S. Weissman, and anonymous referees for advice and criticism.     

Quine's truth

W. V. Quine has made statements about truth which are not obviously compatible, and his statements have been interpreted in more than one way. For example, Donald Davidson claims that Quine has an epistemic theory of truth, but Quine himself often says that truth is just disquotational. This paper argues that Quine should recognize two different notions of truth. One of these is disquotational, the other is empiricist. There is nothing wrong with recognizing two different notions of truth. Both may be perfectly legitimate, even though, to some extent, they may be applicable in different contexts. Roughly speaking, a sentence is true in the empiricist sense if it belongs to a theory which entails all observation sentences which would be assented to by the speakers of the language in question (and no observation sentences which would be dissented from by these speakers). Various objections to this idea are discussed and rejected.