Pobbles wrote:
I might be wrong here... but for most (NT) people their body language is automatic.
This.
For "normal" people, their body language reflects how they feel....at least within given cultural contexts. Interrogations and profiling is highly successful when the interviewer understands cultures, beliefs, etc. and reads the "subtle" cues in body language, voice inflection, etc. when questioning someone.
Someone who can fake that is either well-trained to repress these things or a psychopath.
The problem is when a person's culture/beliefs would produce different responses or a person has a condition where they don't emote properly to reflect what they are feeling. Then, you can't trust the body language.
Still, for the vast majority of society, they rely on the subconscious signals more than the conscious signals to communicate.