Steven A. McCornack

Accuracy in detecting truths and lies: Documenting the “veracity effect”

Deception research has consistently shown that accuracy rates tend to be just over fifty percent when accuracy rates are averaged across truthful and deceptive messages and when an equal number of truths and lies are judged. Breaking accuracy rates down by truths and lies, however, leads to a radically different conclusion. Across three studies, a large and consistent veracity effect was evident. Truths are most often correctly identified as honest, but errors predominate when lies are judged. Truth accuracy is substantially greater than chance, but the detection of lies was often significantly below chance. Also, consistent with the veracity effect, altering the truth‐lie base rate affected accuracy. Accuracy was a positive linear function of the ratio of truthful messages to total messages. The results show that this veracity effect stems from a truth‐bias, and suggest that the single best predictor of detection accuracy may be the veracity of message being judged. The internal consistency and paralleli...

Information manipulation theory

One way of thinking about how deceptive messages are generated is in terms of how the information that interactants possess is manipulated within the messages that they produce. Information Manipulation Theory suggests that deceptive messages function deceptively because they covertly violate the principles that govern conversational exchanges. Given that conversational interactants possess assumptions regarding the quantity, quality, manner, and relevance of information that should be presented, it is possible for speakers to exploit any or all of these assumptions by manipulating the information that they possess so as to mislead listeners. By examining various message examples, it is demonstrated that IMT helps to reconcile previous disagreement about the properties of deceptive messages.

How people really detect lies

A primary focus of research in the area of deceptive communication has been on peoples ability to detect deception. The premise of the current paper is that participants in previous deception detection experiments may not have had access to the types of information people most often use to detect real-life lies. Further, deception detection experiments require that people make immediate judgements, although lie detection may occur over much longer spans of time. To test these speculations, respondents (N=202) were asked to recall an instance in which they had detected that another person had lied to them. They then answered open-ended questions concerning what the lie was about, who lied to them, and how they discovered the lie. The results suggest people most often rely on information from third parties and physical evidence when detecting lies, and that the detection of a lie is often a process that takes days, weeks, months, or longer. These findings challenge some commonly held assumptions about deception detection and have important implications for deception theory and research.

When lies are uncovered: Emotional and relational outcomes of discovered deception

The current article explores the impact that the discovery of deception has upon emotional intensity, negativity of emotional reaction, and relational stability for individuals involved in relationships. Drawing upon contemporary conceptualizations of emotion and cognition, several hypotheses and research questions were developed and tested in a sample of 190 subjects who had recently discovered the lie of a relational partner. The results suggest partial support for the model of emotion that is presented. Increases in relational involvement, importance attributed to the information that was lied about, and importance attributed to the act of lying were all positively associated with reported increases in emotional intensity. Increases in suspicion functioned to enhance reported emotional intensity for situations in which either the lie or the act of lying was judged as significant. From both quantitative measures and open‐ended responses, the importance of the information that was lied about emerged as t...

Linking Love and Lies: A Formal Test of the Mccornack and Parks Model of Deception Detection

This paper reports a replication and extension of the McCornack & Parks model of relational deception detection which argued that the association between relational involvement and accuracy in detecting deception is mediated by judgmental confidence and truth-bias; and that relational involvement, confidence, truth-bias and accuracy form a causal chain. Recent research testing some of these links has yielded results which cast doubt upon the validity of the model. Moreover, research examining suspicion has raised questions concerning the generalizability of the model across various levels of aroused suspicion. The present study represents the first rigorous path-analytic test of the model, as well as a test of the models generalizability. Testing the model in a sample of ninety romantically involved couples, this study found unqualified support for the model as it was originally specified. In addition, the model seems to be generalizable across levels of aroused suspicion. The implications of the model for research on relationships are discussed.

When the Alteration of Information Is Viewed as Deception: An Empirical Test of Information Manipulation Theory.

This study provides the first empirical test of Information Manipulation Theory. IMT posits that individuals manipulate information simultaneously along several different dimensions in verbally deceiving others, the result being a potentially infinite range of specific message types. In the companion to this piece (McCornack, 1992), different deception‐provoking situations were generated, and examples of deceptive messages were produced and analyzed. In this report, messages involving various types of information manipulation were evaluated in terms of perceived deceptiveness and competence. Results suggest that manipulations of amount, veracity, relevance, and clarity of information all significantly influence perceived message deceptiveness and perceived message competence.

The dark side of trust: Conceptualizing and measuring types of communicative suspicion

This paper seeks to enhance understanding of how individuals go about making truth/lie judgments. In this paper, we argue for the existence of three distinct constructs related to suspicion (generalized communicative suspicion or “GCS,” situationally‐aroused or “state” suspicion, and lie‐bias), create and validate a measure of GCS, and provide a test of the relationship between these constructs. Results from three separate studies are reported. The first study tested the dimensionality and construct validity of a newly‐developed measure of GCS. The second study provided a replication of the GCS scales factor structure, and further tested its construct validity by examining the scale in comparison to measures of several related constructs. The third study tested the predictive utility of this measure, and allowed for a test of the relationship between GCS, state suspicion, and lie‐bias. The results of all three studies are consistent with the validity of the GCS measure, and have important implications fo...

Information Manipulation Theory 2: A Propositional Theory of Deceptive Discourse Production

Information Manipulation Theory 2 (IMT2) is a propositional theory of deceptive discourse production that conceptually frames deception as involving the covert manipulation of information along multiple dimensions and as a contextual problem-solving activity driven by the desire for quick, efficient, and viable communicative solutions. IMT2 is rooted in linguistics, cognitive neuroscience, speech production, and artificial intelligence. Synthesizing these literatures, IMT2 posits a central premise with regard to deceptive discourse production and 11 empirically testable (that is, falsifiable) propositions deriving from this premise. These propositions are grouped into three propositional sets: intentional states (IS), cognitive load (CL), and information manipulation (IM). The IS propositions pertain to the nature and temporal placement of deceptive volition, in relation to speech production. The CL propositions clarify the interrelationship between load, discourse, and context. The IM propositions identify the specific conditions under which various forms of information manipulation will (and will not) occur.

Testing the Effects of Nonverbal Behavior Training on Accuracy in Deception Detection with the Inclusion of a Bogus Training Control Group

Previous deception detection training studies have compared people receiving training in nonverbal behaviors associated with deception to control groups receiving no training and found that people who are trained are slightly to moderately more accurate than people who have not been trained. Recent research on the relationships between source veracity and specific nonverbal behaviors, however, suggests that those relationships are weak, inconsistent, and limited to high stakes lies. If specific nonverbal behaviors are not reliable indicators of deception, then one might wonder why training improves accuracy. This paper tests the speculation that the simple act of training, independent of the training content, may improve accuracy simply because those in training conditions process messages more critically. This speculation was tested in three experiments that included both no training and bogus training control groups. The bogus training group was most accurate in Study 1, but this finding failed to replicate in Study 2. A coding study (Study 3) examined behavioral differences in the stimulus tapes. The predicted differences were observed in a final experiment (Study 4) were training was based on the coded stimulus tapes. The results suggest that the effects of training are generally small and highly variable from message to message, that valid training does not produce large improvements over a bogus training control, and that bogus training can produce statistically significant improvements over a no‐training control.

What Women Know that Men don't: Sex Differences in Determining the Truth Behind Deceptive Messages

While a good deal of research has been devoted to studying individual accuracy in detecting deceptiveness, a neglected issue involves the ability of individuals to accurately discern the truth that is obscured by deceptive messages. Methodological considerations have limited the generalizability of previous research findings in this area. Drawing upon a conceptualization of deception as a relational phenomenon, three hypotheses were developed and tested in a sample of 55 premarital romantic dyads. Subjects viewed a series of 12 videotaped segments of their partner who told the truth in half the segments and lied in half the segments. Results indicated that individual accuracy in ascertaining the underlying truth obscured by deception declines as individuals become more intimate. In addition, women were found to be consistently more accurate than men independent of level of relationship development.