Business research conducted by some universities in the Spanish cities of Madrid, Barcelona and Zaragoza has revealed that ninety percent of people fall within four broad personality types. Extensive studies were conducted on volunteers who submitted for this survey. An algorithm was developed to decode the personality types using sophisticated business analytics. The first type includes the “envious” who are happy as long as they are doing better than others. The “optimists” are those who feel that their group can contribute best to resolve any situation. “Pessimists” always join the group that they consider as the lesser of evils. The “trusting” always collaborate with others with little regard to their own gains.

Source:http://www.dailymail.co.uk/sciencetech/article-3827456/Study-finds-90-people-classified-just-four-personality-groups-envious-common.html