Houston, Floyd, and Carnicero dedicate this chapter to debunking widely accepted but unreliable indicators of deception. The authors begin by addressing microexpressions, popularized by the television show Lie to Me, which featured a character who could detect lies through fleeting facial movements. While microexpressions can reveal underlying emotions like fear, anger, or anxiety, the authors identify two critical limitations: There is no specific microexpression that definitively indicates deception, and these split-second movements require highly specialized training to detect accurately in real-time situations.

The chapter systematically examines several “Behavioral Cautions”—indicators that seem logical but prove unreliable in practice. Poor eye contact, often cited as a sign of lying, varies dramatically across cultures and individuals, making it an unreliable deception indicator. The authors note that eye contact serves multiple purposes, from intimacy to challenge, and its absence could indicate discomfort, anxiety, cultural differences, or simple lack of confidence rather than dishonesty. Similarly, closed posture may signal coldness, comfort, or personal preference rather than deceptiveness.

The authors also discuss signs of anxiety, noting that while anxiety often accompanies deception, nervousness can stem from numerous sources: inexperience with authority figures, medical conditions, or natural temperament. The authors also challenge the reliability of preemptive responses (responding to a question before the questioner has finished asking it), explaining that both truthful and deceptive individuals may rush to answer questions, albeit for opposite reasons; truthful people want to share the facts as soon as possible, while deceptive people want to complete their lie and move on.

The chapter discusses “baselining”—establishing normal behavior patterns to identify any deviations from them. The authors argue that baseline approaches suffer from faulty logic; humans are far too complex for such simple comparisons. They warn that intelligent suspects can manipulate their baseline, appearing cooperative during the initial control questions in order to mask deceptive responses later on.

The authors conclude with a case study demonstrating how demographic expectations can lead to the wrong conclusions, describing a teenage girl whose calm demeanor when reporting a sexual assault led investigators to dismiss her truthful account because it didn’t match their assumptions about how victims “should” behave.

In this chapter, the authors’ critique extends beyond simple myth-busting to reveal a fundamental tension between what the public expects from deception detection—dramatic, visually obvious tells—and the subtle, context-dependent reality of human behavior. By positioning their expertise as running counter to popular media portrayals, the authors establish their credibility while addressing the misconceptions that have likely misled countless readers in real-world situations. Their emphasis on the potential for misunderstanding due to things like cultural and psychological differences also addresses a gap in earlier chapters—e.g., Chapter 8, which largely conflates perceptible stress with potential deception.

Chapter Lessons

• Microexpressions don’t necessarily reveal deception, and they require impractical levels of specialized training to identify in real-time situations.
• Common indicators like poor eye contact, closed posture, and nervousness are highly individualistic behaviors that can have numerous explanations beyond lying.
• Baseline approaches to behavior analysis are vulnerable to manipulation and oversimplify the complexity of human behavior patterns.
• Demographic expectations about how people “should” behave in certain situations can lead to serious misjudgments and wrongful conclusions about truthfulness.

Reflection Questions

• Have you ever relied on any of these “Behavioral Cautions” when trying to determine if someone was being truthful? How might recognizing their unreliability change your approach to reading people?
• The chapter’s case study shows how preconceived notions about how victims should behave led to dismissing a truthful account. In what areas of your life might you be making assumptions based on how you think people “should” react in certain situations?