Paul Ekman's work in the 1970s on emotions demonstrated that humans show seven universal emotions. What are those emotions? Charles Darwin, who's known for his work on how animals adapt to their environments, which aides in the explanation of evolution, published a book 100 years earlier suggesting something similar to Ekman. If all humans are showing the same trait it could suggest the trait has become adaptive to our species' survival. Discuss and provide an example of why each emotional facial response may have helped to ensure the survival of humans. For example, anger has likely continued in our species because it shows other members of the group that a person is unhappy, or perhaps it could be a warning sign for aggression. This facial cue would help us decide if we should approach someone or not. It can also inform others to not approach us when we show that facial expression. Because this facial cue provides us with useful information that may explain why we continue to see it in the population.