Scientists have used an algorithm to plot huge data collected from 1.5 million people to define four distinct personality types
Greek physician Hippocrates had said that there are four bodily humours shaped human behaviour which then has resulted in four basic personality types in humans. There haven’t been considerable scientific data to support his theory and thus it has been rejected from time to time. The concept of personality in psychology has largely remained controversial. Many studies have been performed on smaller groups and thus the results generated haven’t been universally accepted as they are difficult to replicate. There has been no scientific data till date to support the concept of personality types.
This notion can finally change as a new study published in Nature Human behaviour has shown that there are four unique clusters of personality types in humans thereby declaring that Hippocrates’ theory was indeed scientifically true. Researchers from Northwestern University have used a massive number of 1.5 million participants in their study to develop a data set. They collected information from four questionnaires for its 1.5 million respondents and combined data retrieved from John Johnson's IPIP-NEO, the myPersonality project and the BBC Big Personality Test datasets. These questionnaires had between 44 to 300 questions and have been comprehensively designed by researchers over years. People voluntarily take these internet quizzes in order to receive feedback on their personality and all this useful data is now available to researchers worldwide for their own investigation and analyses. Only because of the power of internet that it is possible to collect such data easily and all information can be logged. Earlier questionaries’ had to be physically distributed and collected, which required huge manpower and was geographically limited. The most powerful aspect of the current study is the utilization of already available data.
When researchers tried to sort out the data by using traditional clustering algorithms, they experienced inaccurate results which vaguely suggested 16 personality types. So, they decided to change their strategy. They first used standard clustering algorithms to search available data but imposed additional constraints. They they plotted on a quadrant graph on how the data set manifested five most widely accepted traits of personality: neuroticism, extraversion, openness, agreeableness and conscientiousness. These traits called the ‘Big Five’ are accepted as the most reliable and replicable domains of human personality. Looking at the plots, researchers observed four major types of personality based upon their higher grouping. They went ahead and validated the accuracy of new clusters through teenage boys – considered to be vain and selfish – and are definitely the biggest cluster of ‘self-centred’ similar people across different demographics.
The four different groups are defined as reserved, role models, average and self-centred.
a) Reserved people are not open but are emotionally stable. They are introvert and mostly agreeable and conscientious. This trait is the most neutral irrespective of age, gender or demography.
b) Role models are though low in neurotic charactertics but are high in others and have leadership qualities. They are nice, open and flexible to new ideas and most of the time dependable. Women were seen more in this group. And for obvious reasons people more than 40 years of age because the likelihood of being a role model increases with age. Authors state that being around more role models can make life easy and comfortable.
c) Average people are highly extrovert and neurotic and this is the most common type. These people tend to have an average score in all traits and in this group, there are women slightly more than men. According to the authors this would be a ‘typical’ person.
d) Self-centred people as the term suggests are highly extrovert but non-openminded. They are also not agreeable or conscientious or hardworking. Expectedly there are more teenagers in this group especially boys. And no women over 60 years of age are in this group.
The ‘average’ type of personality might be considered as the ‘best’ or ‘safest’.
It is also discovered that as people mature, that is from adolescent to late adulthood, the personality types often shift or change from one type to another. Example people under 20 years of age are generally more neurotic and less agreeable compared to older adults. Such studies done on a large scale displays better results but how these character tics change with age needs to be investigated further. The methodology adopted is being labelled quite robust by experts. Such a study is not only interesting but can be of use to hiring personnel to look for potential people who can be a good fit for a particular job or organisation. It can be a useful tool for mental healthcare service providers to be able to assess personality types which have extreme traits. It could also be used for a dating service to meet suitable matching partner or the complete opposite even as it is believed that ‘opposites attract’.
Martin Gerlach, Beatrice Farb, William Revelle, Luís A. Nunes Amaral 2018, ‘A robust data-driven approach identifies four personality types across four large data set’, Nature Human Behaviour, DOI: https://doi.org/10.1038/s41562-018-0419-z