During class, when I daydream or when I can’t understand the lecture, I nod to the teacher to make him or her think I’m listening. I do it mostly to stay out of trouble, but also to make the teacher feel appreciated. But since I’m not really listening, is nodding and eye contact equivalent to sinning?
If you're alert enough to nod and make eye contact, you are listening more than you thought. But the teacher probably isn't paying attention to you. :D