Study on behaviour identifies four basic personality types

A study on human behaviour has revealed that 90 percent of the population can be classified into four basic personality types: optimistic, pessimistic, trusting and envious. However, the latter of the four types, envious, is the most common, with 30 percent compared to 20 percent for each of the other groups.

This is one of the main conclusions of a study recently published in the journal, Science Advances by researchers from Universidad Carlos III de Madrid, Spain, together with colleagues from the universities of Barcelona, Rovira i Virgili and Zaragoza.

The study analysed the responses of 541 volunteers to hundreds of social dilemmas, with options leading to collaboration or conflict with others, based on individual or collective interests.

Specifically, this work is part of game theory, a branch of mathematics with applications in sociology and economics, which examines the behavior of people when they face a dilemma and have to make decisions. These decisions will have different consequences which will also depend on what the other party involved decides to do.

After carrying out this kind of social experiment, the researchers developed a computer algorithm, which set out to classify people according to their behaviour. The computer algorithm organized 90 per cent of people into four groups: the largest group, accounting for 30 per cent, being the Envious – those who don’t actually mind what they achieve, as long as they’re better than everyone else; next are the Optimists – who believe that they and their partner will make the best choice for both of them – on 20 per cent. Also on 20 per cent are the Pessimists – who select the option, which they see as the lesser of two evils – and the Trusting group – who are born collaborators and who will always cooperate and who don’t really mind if they win or lose.

There is a fifth, undefined group, representing 10 per cent, which the algorithm is unable to classify in relation to a clear type of behaviour. The researchers argue that this allows them to infer the existence of a wide range of subgroups made up of individuals who do not respond in a determined way to any of the outlined models.

One of the authors of the study, Anxo Sánchez, who is a professor in GISC (Grupo Interdisciplinar de Sistemas Complejos / Interdiscip-
linary Group of Complex Systems), which is part of the Department of Mathematics at Universidad Carlos III de Madrid (UC3M), Spain, explained: “Those involved are asked to participate in pairs, these pairs change, not only in each round, but also each time the game changes. So, the best option could be to cooperate or, on the other hand, to oppose or betray ….. In this way, we can obtain information about what people do in very different social situations.”