High sexual appetite and compulsive promiscuity rule Erica’s life. Bill’s is governed by a drive to make money; he was worth several million pounds by the age of 40, he then blew it all but is now obsessed with rebuilding it. These two have one thing in common. They both have high scores for extraversion, one of five personality characteristics.
Daniel Nettle, an academic psychologist, guides us through a key theory of psychology, that all human personalities can be accurately mapped by assessing five simple measures. The five-factor model scores people for their levels of extraversion, neuroticism, conscientiousness, agreeableness and openness. He then examines why such a range of personality should have been preserved through evolution, arguing that there are merits in all the traits. For example, having a low agreeableness score, which indicates a lack of empathy, might serve someone well in a society where a high-status goal-seeking approach is valued strongly. Conversely, women tend to score significantly higher for agreeableness, which hints at the advantages of having a social network when raising children.
When Nettle uses real people to illustrate each characteristic the book zips along and you’re hooked. The quirks of those high in extraversion are fascinating as are the misfortunes that befall those who have high neuroticism. Unfortunately, the chapter on openness (creativity) does not include any examples of real people interviewed by the author for his research. Instead it relies on an analysis of Allen Ginsburg’s poem Howl, a poor substitute. Lack of real anecdotes left this section difficult to engage with and it reads like a theoretical exercise. Maybe Nettle couldn’t find any good examples – do creative people just not like filling in research questionnaires?
Nettle is a good explainer of the issues he discusses and the analogies he uses make his subject easy to understand. There is a great quiz at the back to find out your own personality type. The evolutionary perspective he takes is interesting and affirming – there is no such thing as a “good” or a “bad” personality, all have some evolutionary advantages. But his detailed detour into the variation of beaks of finches on the Galapagos Islands and evolution seems a bit out of place in a book whose main audience will be those interested in understanding their own personality. If you want a book simply about personality then this probably isn’t the one for you.