On the stability of personality


in Geek stuff, Psychology, Science

One of the most interesting questions arising within biology, psychology, and philosophy is: “What are we?”.

We aren’t a particular collection of atoms and molecules, because that is constantly in flux. With every breath we take and meal we eat, we incorporate matter from the world into our bodies. At the same time, we lose matter whenever we exhale or excrete. A carbon or nitrogen atom that is in your brain or bone today could be in your blood tomorrow and in the air or your local river tomorrow. There are probably hardly any of the atoms you were born with still inside your body, and few of the atoms inside your body now will be there when you die.

We also aren’t disembodied souls or spirits. Our minds and the experience of mental life are fundamentally tied to our physical brains in predictable ways. There are structures within the brain that operate the various features of mental life, and our experiences are related to them. These things change in response to physical stimuli, such as exposure to psychoactive drugs or a brick to the head. There isn’t some abstract ‘I’ that enjoys cycling and coffee, but which dislikes intense heat and polka music. Rather, those preferences reflect changeable facts about my mind and brain. If I fell in love with a polka musician, my feelings about the genre could change. Similarly, with a few more spectacular crashes, my ardour for cycling could diminish.

There is one partial answer to the identity question that has arisen from psychology. Psychologists have identified a ‘Big Five’ set of personality traits that vary between individuals but which tend to remain stable for a particular individual over time. If you test a group of young children, you will find that they score differently from one another on the five traits. But if you come back decades later and test the results, they will likely score similarly to how they did as children.

As described by Wikipedia, the traits are:

  1. Openness – (inventive/curious vs. consistent/cautious). Appreciation for art, emotion, adventure, unusual ideas, curiosity, and variety of experience.
  2. Conscientiousness – (efficient/organized vs. easy-going/careless). A tendency to show self-discipline, act dutifully, and aim for achievement; planned rather than spontaneous behaviour.
  3. Extraversion – (outgoing/energetic vs. solitary/reserved). Energy, positive emotions, surgency, and the tendency to seek stimulation in the company of others.
  4. Agreeableness – (friendly/compassionate vs. cold/unkind). A tendency to be compassionate and cooperative rather than suspicious and antagonistic towards others.
  5. Neuroticism – (sensitive/nervous vs. secure/confident). A tendency to experience unpleasant emotions easily, such as anger, anxiety, depression, or vulnerability.

Thinking about myself, I can pretty easily estimate where I lie with respect to others on each of these:

  1. I think I am unusually open. If someone offered me an interesting job in Paris or Tokyo tomorrow, I would take it. At the same time, I am not the sort of person willing to devote their entire life to the search for novelty. I do enjoy learning and using difficult words, spending time on reflection, and considering abstract problems. I would find myself hopelessly frustrated and bored in a life with no novelty, even if it was very comfortable.
  2. I also think I am unusually conscientious. I have been following a personal strategy for years that has involved a fair bit of investment and delayed gratification. I like keeping to-do lists, and I rarely miss appointments or allow things to ‘fall through the cracks’. I rarely lose things.
  3. I am on the borderline between introversion and extroversion. At the wrong sort of party (with dancing), I am likely to be at the edge, but I am likely to be right in the middle of a party that is to my liking (with talking). I am generally comfortable around people and open to talking to strangers. At the same time, I definitely need solitude and time to myself. I would never be happy in a life that afforded no opportunities to be alone.
  4. Compared to most people, I don’t think I am especially agreeable. I tend to be critical and judgmental and I do not care very much about feelings for their own sake. At the same time, I think having people of that sort is defensible and necessary. For injustice and wrongdoing to be stopped, there need to be people who will speak out against it. Similarly, if we give excessive attention to how people feel, we risk ignoring the facts in any particular situation.
  5. I am more neurotic than most. I wouldn’t be the person who I am if I didn’t worry about climate change every day. To reverse the tautology, If I didn’t worry about climate change every day, I would not be the person who I am. I don’t usually feel much anger, but I do get anxious and sometimes depressed. I worry a lot, and my moods vary a great deal.

All this seems like an important part of the answer to the identity question. These personality traits tend to remain stable across the course of a normal human life (if you get a railroad spike through your head all bets are off about the stability of your personality). They are not substantially altered by common but important occurrences like adolescence, emergence into adulthood, marriage, reproduction, or aging. Even though the traits probably arise from a combination of genes and experience (studies suggest that about half of the explanation for how we score is genetic), this nonetheless seems like a valid and useful way to understand the meaning of an individual.

{ 6 comments… read them below or add one }

R.K. March 11, 2011 at 6:19 pm

I doubt there is anything inherent about these traits. They are just labels that can be applied with a good degree of consistency.

. May 10, 2011 at 6:41 pm

“Most profoundly, children do not allow their personalities to be shaped by their parents’ nagging, blandishments, or attempts to serve as role models. As we shall see in the chapter on children, the effect of being raised by a given pair of parents within a culture is surprisingly small: children who grow up in the same home end up no more alike in personality than children who were separated at birth; adopted siblings grow up to be no more similar than strangers.”

Pinker, Steven. The Blank Slate: The Modern Denial of Human Nature. p.249 (paperback)

Anon March 22, 2012 at 6:10 pm

Strange thought: we’re already undead. Our bodies don’t contain any of the original cells we were born with. All those cells have died and been replaced by others serving the same functions.

. May 21, 2012 at 5:55 pm

Online Alignment Test
David Noonan

. June 3, 2013 at 5:32 pm

The results mostly suggest favorable psychological characteristics of BDSM practitioners compared with the control group; BDSM practitioners were less neurotic, more extraverted, more open to new experiences, more conscientious, less rejection sensitive, had higher subjective well-being, yet were less agreeable.


. July 2, 2013 at 2:54 pm

She found that different people rated the same animals in the same way. That suggests their assessments were reliable. She also found that scores for particular terms tended to cluster together. A chimp that scored highly for irritability, for example, was also likely to score highly for aggression and for jealousy, and to have low scores for calmness and relaxation. That let her apply a statistical technique called principal-component analysis to the data, to work out the dimensions of chimpanzee personality.

It is analysis of this sort which showed that human personas have five dimensions. Chimps’ personas, by contrast, seem to have six. These are extroversion, agreeableness and openness, which match human dimensions, and reactivity (the cluster described above), dominance and methodicalness, which do not. Reactivity is similar to the human dimension called neuroticism, though not similar enough, in Dr Freeman’s view, to justify the same label. And methodicalness, which measures the way animals approach things like using tools and making the nests they sleep in, resembles conscientiousness—though Dr Freeman’s raters found this difficult to assess because such activities are not much available to the chimps in Texas. But there is, intriguingly, no human dimension that resembles chimpanzee dominance.

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