This article explains how microexpessions are accurate, yet hard to read consistently. These microexpressions display varying emotions that can help humans stay out of danger, comfort a friend, etc.

This article explains that perhaps facial expressions are misleading. Instead, people should look at other people's body language to find out unsaid emotions.

An explanation of sarcasm, how we use it, and why we use it.

This article gives an overview of sarcasm and how hard/easy it is to detect it.