Following up on the discussion I started last time about the Big Five personality traits, I want to provide a little more context on the Big Five and how they relate to the field of personality testing as a whole. The Big Five are personality dimensions that describe the ways in which an individual reacts to other people and to the world around them. For example, the Extraversion/Introversion dimension describes the extent to which an individual is more or less outgoing, gregarious, and in need of social stimulation. If a personality test determines that an individual is in the 65th percentile for "Extraversion," this means that the individual is more extroverted than 65 percent of the individuals in the norm group.
The notion of personality "traits" is now fairly widely accepted and is superseding an older paradigm of personality "types" that originated with Carl Jung and relied on a view of personality that grouped people into one of two distinct types, such as introvert or extravert, thinker or feeler. The traits model is gaining credence in personality research because of growing evidence that suggests that a strict dichotomy between two distinct types does not sufficiently describe the nuances in the extent to which individuals tend to one side or the other.
The best known example of a test based on the older model is the Myers-Briggs Type Indicator (MBTI). Since the MBTI is probably the most widely known and thoroughly studied personality test today, and since we get asked about it all the time, I thought I'd offer some thoughts on it. Or one thought, to be exact. Do not use the MBTI to make hiring decisions! I repeat, the MBTI should not be used for the purpose of employee selection...ever. I say this because the MBTI, which has a large and enthusiastic following, is often used in just this way, even though it shouldn't be. There are many reasons the MBTI should never be used to inform hiring decisions. But the most important is simply that there's no convincing evidence to link MBTI results to job performance. In order to ward off the anticipated deluge of angry emails from MBTI-devotees, I would just say that if you don't believe me, take it from the MBTI's publisher. Even they do not suggest it should be used for employee selection...they provide a table that lists every conceivable use for a test but note the complete lack of check marks in the "Selection" column.
There's plenty of evidence, on the other hand, to link the Big Five Traits to job performance for a variety of positions. Conscientiousness, which measures the extent to which an individual is reliable, organized, persistent, and responsible (those who score low in Conscientiousness may be more impulsive and at times unreliable) has been shown to be moderately predictive of success across many job types, but particularly for entry-level positions where characteristics like reliability and punctuality may be more valuable than creativity. Certain Big Five traits are useful for certain types of jobs; for example, extraverts perform better in sales than do introverts, and highly agreeable people are well-suited for customer service but might not make good judges or CEOs, because those jobs require objective decision-making that highly agreeable people may not be comfortable with. Other Big Five traits are much less relevant to employee selection: for example, there isn't much evidence that Openness (the extent to which an individual is imaginative and creative, rather than down to earth and conventional) is predictive of work success, even though it seems logical that people with high Openness scores would be better suited for jobs that require imagination, creativity or abstract thinking.
Alright, that's enough for now. Next time I'll finish up with this thread by discussing ways in which some employment personality tests move beyond the Big Five by measuring more fine-grained traits that have been shown to predict success for specific jobs.