The age-old question asks: Is it nature or nurture? What makes us the way we are? Why does one person want to bungee jump over a river gorge while their sibling cautiously stands back from the railing? Daniel Nettle in Personality: What Makes You the Way You Are examines the mysterious and complex topic of human personality and answers the nature/nurture question with a “yes, it is both” answer. This psychology book traces study that goes back to the late 1800s, leaning heavily into evolutionary theory. Nettle’s premise of understanding personality aims at a broad audience. “This book is aimed at the interested general reader, rather than just my academic colleagues.” The book contains a mix of theory, research, and personal stories to illustrate the points.
Nettle begins with foundational principles of personality. “Personality traits are meaningful, stable, partly genetically inherited consistencies in classes of behaviour.” By meaningful, the author relates personality traits to certain behavior characteristics common to that trait. By stable, Nettle argues for the unchanging nature of personality. In other words, we cannot change personality type, only improve the characteristics of our personality type(s). By saying partly genetic he points to emerging research of biological connection to personality. “Though the techniques are new, they are already yielding evidence that personality traits have a discoverable brain basis.” At the same time, environment also plays a role in the development and manifestation of personality.
The core of Personality explores what Nettle calls the “big five” personality traits. A chapter is devoted to each. The big five includes: Extroversion (titled “wanderers”), Neuroticism (“worriers”), Conscientiousness (“controllers”), Agreeableness (“empathizers”), and Open-mindedness (“poets”). Nettle believes that each personality type possesses a positive aspect. One might wonder about the positive application of Neuroticism, but there are times when worry is legitimate and beneficial. A few points of interest emerged for me in this reading.
In the chapter on Extroversion, Nettle articulates a connection to dopamine as a significant reason for the trait. “There is converging evidence, then, that what makes an extravert an extravert is a high degree of responsiveness in a suite of dopamine-driven brain areas…” Similar to Lieberman and Long, Nettle connects a chemical to behavior and personality. In a departure from what I recall in The Molecule of More, Nettle argues that “addictions are really about the failure to inhibit a once-rewarded behaviour, not about the degree of euphoria that is created.” He admits the connection between positive response and Extroversion. However, when it comes to predicting addiction, “in studies of which personality characteristics predict the development of addiction problems, it is Conscientiousness rather than Extroversion which features.” This conclusion seems at odds with the conclusions I took from Lieberman and Long. I would reread their work to confirm or deny that if I had more time.
In the chapter on Conscientiousness, Nettle makes a bold statement about the impact of scoring high in this trait. “Conscientiousness is the most reliable personality predictor of occupational success across the board…In general, the higher Conscientiousness score you have, the better you will do, other things being equal.” He does admit a weak connection, but one that shows up consistently. One may be tempted to equate this trait with intelligence. However, Nettle debunks that thought, suggesting that intelligent people score low in this trait due to innate abilities allowing for their intellect to substitute for self-discipline.
Those first two observations stirred curiosity in me. The last one includes application to my leadership role. While Nettle contends that personality traits cannot be changed, growth within traits can. Instead of wishing away one’s traits, “it is rather a question of finding fruitful expressions of the profile we happen to have inherited by capitalizing on the strengths and minimizing the effects of the weaknesses.” Each personality type contains the potential for great good and full life. What one spends their time working on within themselves matters.
In my earlier years of ministry, several sources that spoke into my life encouraged me to strengthen my areas of weakness. The thought centered on the model of a well-rounded leader. Nettle and others like Marcus Buckingham in his book Go Put Your Strengths to Work argue for leveraging strength, not shoring up weakness. Great time and energy may increase one’s weakness, but that time and energy produce more return by building one’s strengths. Over the years, this principle shaped my hiring practice to be “staff to my weaknesses.” In other words, hire people who are strong where I am not. For example, I am not a good counselor. I wish I was, but alas, I am not. A few people on the staff excel at counseling. Those seeking counselor receive better input from someone other than me. When a leader spends most of her/his time in their area of strength, everyone wins.
 Daniel Nettle, Personality: What Makes You the Way You Are (New York: Oxford University Press, 2007), 13.
 Ibid., 52.
 Ibid., 38.
 Ibid., 96.
 Ibid., 139.
 Ibid., 138.
 Ibid., 142.
 Ibid., 245.