In the end, body language conveys important but unreliable clues

The Truth Behind the Smile and Other Myths - When Body Language Lies - HBS Working Knowledge

The Truth Behind the Smile and Other Myths - When Body Language Lies

Myths:

1. A liar can’t look you straight in the eye.

2. When meeting someone, the more eye contact, the better.

3. Putting your hands behind your back is a power gesture.

4. “Steepling” your fingers shows that you’re intellectual.

5. High-status people demonstrate their dominance of others by touching them.

6. People smile when they’re happy.

7. Voices rise when speakers are angry.

8. You can’t trust a fast-talking salesman.

…Most of the research into nonverbal communications shows that people are not very good at masking their feelings. Emotions do leak out regularly, in many ways. And yet, the research also shows that most of us are not as good at decoding those emotions as we would like to think. Young people are significantly worse at both signaling emotions and reading them. Although we do learn as we grow older, we should remain wary; in the end, body language conveys important but unreliable clues about the intent of the communicator. The more information you can get about the clues you are trying to decode, the more likely you will be to decode them correctly.

Very interesting, there are many books and courses that use these myths to “make you a greater person at the eyes of people”. Great, nbully.