Development and Theory

The inception of the big five theory relied upon the assumption that language was a good tool for investigating the underlying traits in human personality. The next stage built upon the lexical hypothesis and instead used self-assessment tests to see if the original hypothesis could be grounded in more compelling statistical evidence.

Over a period of decades, hundreds of thousands of big 5 questionnaires have been filled and returned to psychological researchers. In the era of modern computing, scientists have the capacity to carry out forms of analyses which were impossible in the mid 20th century. The prime form of analysis used on big 5 tests is that of correlational analysis.

Imagine that we have a personality test, which has been filled out by 1,000 respondents. One question is "Do you have lots of friends?" A second question is "Do you enjoy spending time in crowded social settings?" Now what happens when we compare the data sets for these two answers? Of the people who answered yes to question one, what proportion answered yes to question two? What of those who answered no to the first question? What we find is that people who answered yes to question one are much more likely to answer yes to question two (compared to those who answered no to question one). People who answered no to question one are more likely to answer no to question two (compared to those who answered yes to question one).

No matter what the answer, most people will tend to give the same answer to both of these questions. No to both or yes to both. Another way of describing this phenomenon is to say that there appears to be a strong positive correlation between answers to these questions. This suggests that these two traits (having many friends and appreciating crowded environments) are manifestations of some deeper trait. Big 5 theory calls this trait "Extraversion" (not "Extroversion").

A third question is "Have you tried or would you like to try bungee jumping?" The connection between crowded social settings and a wide circle of friends seems like an intuitively obvious one. People make friends in social settings. People who don't like social settings won't make so many friends. And so on. But what about question three? What does bungee jumping have to do with social interaction or tolerance of crowds? We might expect there to be no correlation between the answers to question three and questions one and two. Actually we find yet again that there is a strong correlation. People who have many friends and enjoy busy social settings are much more likely to be interested in bungee jumping than people who have few friends and avoid social settings. The specific trait described by this question is usually referred to as "Excitement Seeking".

This is the point where the merits of such meticulous analytical techniques become clear. Personality theories that pre date these techniques (and the technologies that facilitate them) would have been hamstrung by intuitive assumptions about which traits should be regarded as belonging to the same group and which should not. The virtue of statistical analysis is that it provides the observer with hard data, which forces him to overcome his preconceptions of how he thinks personality ought to work. As with other counterintuitive theories (e.g. Evolution theory, Spherical Earth theory) statistical analysis forces us to acknowledge the gap between our intuitive assumptions and how things really are.

A fourth question is "Do you often feel happy?" By this point you may be recognising the profile of a typical Extravert and you may assume that answers to this question will once again correlate with the answers to the previous three questions. Your assumption would be correct. People who have many friends, enjoy social settings and are interested in bungee jumping tend to experience more positive emotions than people who answered no to the first three questions. These are all traits of Extraversion. Because Extraversion itself is referred to as a "trait", these sub-traits are typically referred to as "facets" to avoid confusion.

A fifth question reads "Do you often feel sad?" Our intuitive assumption might be to expect a strong inverse correlation between question four and question five. Happiness and sadness are opposites aren't they? Someone who often feels sad probably doesn't often feel happy? Actually we find that there is very little correlation between these two questions. People who answer yes to question four are no more likely to answer no to question five than those who answered no to question four. The world appears to consist of a mix of people: those who are both happy and sad; those who are happy and not sad; those who are sad and not happy and those who are neither happy nor sad. Happiness and sadness do not appear to be strongly correlated and do not appear to be controlled by the same underlying trait.

A Sixth question reads "Do you tend to feel awkward in social situations?" Of the five previous questions, which would you expect the answers to question six to correlate with most strongly? Perhaps you might assume the strongest correlation would be an inverse correlation with question two. Those who feel socially awkward presumably will not tend to seek out social situations to any great degree. Actually we find that the answers to question six correlate most strongly with answers to question five. People who say that they often feel sad are much more likely to say that they often feel socially awkward. The answers to questions six and two paint the same counterintuitive picture as the answers to questions four and five. There are sociable people who feel awkward; Unsociable people who feel awkward; Sociable people who don't feel awkward and unsociable people who don't feel awkward. Likewise, the correlations between answers to question six and answers to all of the first four questions are low. Clearly social awkwardness is not influenced by the trait that undergirds questions 1-4 (Extraversion) and is instead influenced by the trait which determines the answers to question five. Sadness and social awkwardness are correlated. The underlying trait for these two facets is called "Neuroticism."

This explanation hopefully gives you a reasonably thorough grounding in the method by which big five research has been developed and continues to be developed.