Case File 208 · Investigation Psychology

Is Defensiveness a Sign of Lying?

By Murder Book Editorial TeamPublished by Gungrounds, the studio making Murder BookPublished 3 October 2026Updated 3 October 2026

No. Defensiveness is an emotional reaction to feeling accused or disbelieved, not a reliable indicator of lying. Innocent people frequently become defensive, irritated or protective of themselves precisely because they are telling the truth and fear they will not be believed. The same reaction can occur in someone who is lying, which is exactly why it cannot tell the two apart. Decades of deception research find that emotional and nervous behaviours are weak cues to deceit, and that treating a defensive reaction as evidence of guilt is one of the classic mistakes in judging honesty.

Key takeaways

Defensiveness is a response to feeling accused, and honest people show it as readily as dishonest ones.
Research finds nervous and tense behaviours are weak, unreliable cues to deception.
The "Othello error" describes mistaking a truthful person's distress at being doubted for a sign of guilt.
Accusatory questioning can itself provoke defensiveness, then that defensiveness gets read as guilt.
People judge lies at about 54% accuracy, so a defensive manner should never be treated as proof.

What do people mean by "defensiveness"?

Defensiveness is a cluster of reactions people show when they feel attacked or disbelieved: pushing back against a question, becoming irritated or angry, justifying themselves, refusing to engage, or insisting repeatedly on their innocence. In everyday life we often read these reactions as suspicious, on the assumption that an innocent person would stay calm and cooperative while only the guilty would bristle.

The assumption does not hold up, for a simple reason. Defensiveness is driven by how a person feels about being accused, not by whether their account is true. Being doubted is unpleasant and threatening whoever you are, and many truthful people respond to it with exactly the heat and resistance we wrongly associate with guilt.

Why is defensiveness not a reliable sign of lying?

The research on behavioural cues to deception is consistent on this point. The 2003 meta-analysis by Bella DePaulo and colleagues, which combined 1,338 estimates of 158 possible cues, found that most behaviours have no reliable link to lying. Liars were, on some measures, a little more tense, but tension and negative emotion were weak cues and plainly shared with anxious, upset or indignant truth tellers. Nothing in that body of work identifies a defensive or confrontational manner as a marker of deception.

The accuracy evidence tells the same story. Charles Bond and Bella DePaulo's 2006 meta-analysis found people judge lies and truths at about 54% accuracy, barely better than chance, and a 2019 review by Aldert Vrij, Maria Hartwig and Pär Anders Granhag concluded that behavioural cues to deceit are faint and unreliable and that observers who rely on them stay poor lie catchers. A defensive reaction is emotion, and emotion cannot be read backwards to a cause. The same caution applies to the closely related belief that nervousness is a sign of lying. For the broader argument, see why there is no single reliable sign of deception.

The Othello error: mistaking distress for guilt

Psychologists have a name for the specific mistake behind this myth. The psychologist Paul Ekman called it the Othello error: the failure to recognise that a truthful person under suspicion may show fear or distress that looks just like the behaviour of a liar who is afraid of being caught. The name comes from Shakespeare's play, in which Othello reads his innocent wife's emotional distress as proof of betrayal, when in fact she is distraught precisely because she cannot convince him of the truth.

The point is not that distress means innocence; it is that distress, defensiveness and fear are ambiguous. They tell you a person feels threatened by the accusation. They do not tell you why. A guilty person may fear exposure, and an innocent person may fear a wrongful outcome, and both can produce the same defensive behaviour. An observer who assumes defensiveness equals guilt simply discounts the second, equally likely, explanation.

This ambiguity is reinforced by how widespread the stereotype is. A large cross-cultural survey by the Global Deception Research Team found that people around the world tend to believe liars are nervous and shifty, the very traits an accused but honest person may display. The belief is common, consistent across cultures and still wrong.

How does accusatory questioning create the very defensiveness it then blames?

There is a further twist, documented in the research on interrogation. The style of questioning can manufacture defensiveness and then misread it. In a 2003 study by Saul Kassin, Christine Goldstein and Kenneth Savitsky, interrogators who were led to presume a suspect was guilty asked more guilt-presumptive questions, applied more pressure and used more techniques, especially against suspects who were in fact innocent. Neutral observers who later watched these exchanges rated the suspects as more defensive, and as somewhat more guilty.

In other words, presuming guilt set off a cycle: the interviewer's pressure provoked a defensive reaction, and that reaction was then taken as confirmation of guilt. Innocent people, pushed hardest, looked worst. This is one reason modern, information-gathering interview methods favour open questions and rapport over confrontation. You can compare the two styles in accusatorial versus information-gathering interrogation, and the same dynamic helps explain why innocent people sometimes confess.

What can defensiveness actually tell you?

Only that a person feels accused, pressured or disbelieved, which is useful human information but not evidence of deception. The sensible response to a defensive reaction is the same as for any behaviour: treat it as a prompt to lower the temperature, ask clearer questions, and look for facts that can be checked independently. What defensiveness cannot do is settle whether an account is true. Reading it as a confession risks exactly the error that sends investigations in the wrong direction. For the wider question of how much behaviour can ever tell us, see can you actually tell when someone is lying?.

Is there a game that takes this seriously?

Murder Book: The Art of Interrogation, from the Croatian studio Gungrounds, is a narrative interrogation game built on this kind of uncertainty. Inspired by real police footage and psychological interviews, it asks you to weigh unreliable stories, contradictions and behavioural changes across a case rather than convict someone for bristling at a question. Development materials describe a casebook of behaviours to notice and an evidence board for linking statements, and its case results even include a "not guilty" outcome, a reminder that pressure and emotion are not the same as proof.

That design reflects the research: a defensive reaction is a reason to ask a better question and to seek corroboration, never a verdict. Murder Book is in development for PC (Steam) and mobile, with release currently planned for the end of Q2 2027, and its cases are built for focused 5–10-minute sessions.