Emotion depends on the circumstance

Charles Darwin popularized the theory of emotional fingerprints - that each emotion creates a specific combination of facial expression, body language, and other physiological cues such as a heart rate.

But recently detailed analyses suggest there is no such thing. Each emotion is represented by a whole range of reactions. The way we interpret our body's signals, such as excited or anxious, depends entirely on the context of the situation and can be easily framed by our expectations.