I think this’ll help you get a picture of what your textbook is describing. As a kid, I used to get into trouble a lot. Frankly I was just clumsy and so error prone. But something always amazed me until my mother told me about it recently. Whenever I got into trouble, she would always know it. She would ask me, for example, who broke her new china and even though I was responsible, I would tell her it wasn’t me. But as soon as I said this, she would pull my ear and give me a good spanking. Every single time I did something wrong and she asked me about it and I invariably denied, she would know I was lying. I used to think maybe she could read my mind. As I got older, I just learned to tell her the truth and at least earn forgiveness by telling the truth.

Recently, we were having thanksgiving dinner and we were all reminiscing about our childhood. It was then that she told me that every time I lied, I never looked her in the eye and I shifted from one foot to the next. She even told me that I rub my hands together because they became sweaty. Apparently, when I lie, my mouth is saying one thing whereas my body language is saying something completely different and since we have no control over our body language, it’s usually more reliable than the things we say.