When interpreting body language for signs of deception or aggression, the BSIS curriculum cautions officers to:

Explanation

Modern body-language and deception research — including Paul Ekman's work — emphasizes that single signals (eye contact, fidgeting, sweating) have high false-positive rates and may reflect cultural norms, neurodivergence, anxiety, medical conditions, or simple discomfort with authority. Officers are trained to look for clusters of behaviors, baseline against the individual's normal demeanor, and treat indicators as cues for further inquiry — not proof. Stereotypes (b) violate civil-rights training and lead to bias-based policing. Accusatory questioning (c) damages credibility and may produce false confessions.