Humans express emotions semi-involuntarily through their facial features and tone of voice. Subtle differences in eyebrow position or mouth shape can convey different meanings. Attempts by aliens to mimic something as simple as a happy smile can actually convey completely different and unintended meanings. Markings or anatomical structures that resemble human facial features like eyebrows can give aliens a permanent scowl or meek expression. To make everything harder, humans can fake expressions
If one was not familiar with human behavior, they may assume that humans have telepathic abilities. Humans are able to convey simple thoughts with each other by flexing and relaxing certain muscles in their face and using specific yet subtle body language. They call this behavior “expressing emotions”. Emotions are a very confusing concept, even humans have difficulties understanding them at times. Essentially, emotions are a physical feeling resulting from the release of certain chemicals in the human brain that can be expressed through movement and facial shapes. This is not even the most complicated thing about emotions. Humans will typically change their demeanor when approaching each other based on the emotions they are feeling themselves and the emotions that the other human appears to be expressing. Unfortunately, it can be extremely difficult to read emotions. Some humans are very gifted at being able to understand another’s emotional state, others could not tell you what other humans are feeling if their lives depended on it (not that you should ever threaten a human to see how well they can interpret emotions, that is highly frowned upon). To add more difficulties to this already completely mystifying behavior, humans are able to pretend to have one emotional state while being in a totally different one. Also, the typical facial expressions for certain emotions do not necessarily always translate to that emotion. For example, when a human stretches out their lips and curl them upwards (otherwise known as smiling) usually this will mean that they are happy or feeling good, uplifting emotions. But, smiles can also indicate fear, contempt, self-deprecation, and a number of other emotions. They are endlessly contradictory and it is infinitely frustrating.
