Spanish researchers published a study in Science Advances that says that 90 percent of the world’s population falls into one of four basic personality types: Optimistic, Pessimistic, Envious and Trusting.

The study was conducted by taking groups of people and pairing them into rotating teams of two. The teams were presented with social dilemmas and were given options that led to either collaboration or conflict.

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Breaking down the types, the study defines Optimists as those who made choices that benefited both people in the pair. Pessimists, the study found, typically chose the lesser evil. Envious types didn’t seem to care about the method as long as the result benefited them over others and Trusting people favored cooperation and collaboration with no consideration on who, if anyone, would benefit in the end.

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The study found that the most people fit into the Envious category. Which do you think you fit?