Authors: Dean Burnett
But even if people were dedicated enough to investigate the actual personality or intellectual changes Gage had experienced, how would they do this? IQ tests were half a century away, and that's just one possible property that might have been affected. So Gage's case led to two persistent realizations about personality: it's a product of the brain, and it's a real pain to measure in a valid, objective manner.
E. Jerry Phares and William Chaplin, in their 2009 book
Introduction to Personality
,
1
came up with a definition of personality that most psychologists would be willing to accept: “Personality is that pattern of characteristic thoughts, feelings, and behaviors that distinguishes one person from another and that persists over time and situations.”
In the next few sections, we're going to look at a few fascinating aspectsâthe approaches used to measure personality, what it is that makes people angry, how they end up compelled to do certain things, and that universal arbiter of a good personality, sense of humor.
Nothing personal
(The questionable use of personality tests)
My sister Katie was born when I was three, when my own puny brain was still relatively fresh. We had the same parents, grew up at the same time, in the same place. It was the 1980s in a
small isolated Welsh valley community. Overall, we had very similar environments, and very similar DNA.
You might expect us to have very similar personalities. This is the opposite of what happened. My sister was, to put it mildly, a hyperactive nightmare, whereas I was typically so placid you had to poke me to make sure I was conscious. We're both adults now, and still largely different. I'm a neuroscientist; she's an expert cupcake maker. This may seem like I'm being condescending, but I'm really not. Ask anyone what they'd prefer: a discussion on the scientific workings of the brain or a cupcake. See which one is more popular.
The point of this anecdote is to show that two people with very similar origins, environments and genetics can still have vastly different personalities. So what chance does anyone have of predicting and measuring the personalities of two total strangers from the general population?
Take fingerprints. Fingerprints are basically the pattern of ridges in the skin at the end of our digits. Yet, despite this simplicity, almost every human on earth has unique fingerprints. If surface patterns of small patches of skin offer enough variety for everyone to have his or her own exclusive set, how much more variety is possible with something that is the result of countless subtle connections and complex features of the human brain, the most complicated thing in the universe? Even to attempt to determine someone's personality with a simple tool like a written test should be utterly futile, a task akin to sculpting Mount Rushmore with a plastic fork.
However, current theories argue there are predictable and recognizable components of personalities, labeled “traits,” that can be identified via analysis. Just as billions of fingerprints conform to just three types of pattern (loops, whorls and arches)
and the vast diversity of human DNA is produced by sequences of just four nucleotides (G, A, T, C), many scientists argue that personalities can be viewed as specific combinations and expressions of certain traits, shared by all people. As J. P. Gillard said in 1959,
2
“An individual's personality, then, is his unique pattern of traits.” Note how it says “his”; this was the 1950s, and of course, women were allowed to have personalities only from the mid-1970s.
But what are these traits? How do they combine to form a personality? Arguably the most dominant approach at present is the “Big 5” personality traits, which argues that there are five traits in particular that make up a personality, in the same way that multiple colors can be made by combining red, blue and yellow. These traits are often consistent across situations and result in predictable attitudes and behaviors in an individual.
Everyone supposedly falls between two extremes of the Big 5 traits:
Openness
reflects how open to new experiences you are. If invited to see a new exhibition of sculptures made out of rotten pork, people at the extremes of openness may say, “Yes, definitely! I've never witnessed art made of rancid meat, so this will be brilliant!” Or, “No, it's in a different part of town from where I usually am so I won't enjoy it.”
Conscientiousness
reflects the extent to which someone is prone to planning, organizing, self-discipline. A very conscientious type might agree to attend the rotten-pork exhibition, after working out which would be the best bus route with alternatives in case of traffic disruptions, and also getting a tetanus booster. A non-conscientious type would just agree to meet there in ten minutes, not ask permission to leave work
early and opt to follow their nose to find the location.
Extroverts
are outgoing, engaging, attention-seeking, while introverts are quiet, private and more solitary. If invited to the rotten-pork exhibition, an extreme extrovert will attend and bring their own hastily made sculpture to show off, and end up posing alongside all the exhibits for their Instagram account. An extreme introvert wouldn't talk to someone long enough to be invited.
Agreeableness
reflects the extent to which your behavior and thinking is affected by a desire for social harmony. A very agreeable person would surely agree to attend the rotten-pork sculpture exhibition, but only as long as the person inviting didn't mind (they don't want to be a bother). Someone totally lacking in agreeableness probably wouldn't be invited anywhere by anyone in the first place.
A
neurotic
person is invited to a rotten-pork sculpture exhibit and they decline and explain why in exquisite detail. See: Woody Allen.
Unlikely art exhibitions aside, these are the traits that make up the Big 5. There's a lot of evidence to suggest they're quite consistent: a person who scores high on agreeableness will show the same tendencies in a wide variety of situations. There is also some data linking certain personality traits with specific brain activity and regions. Hans J. Eysenck, one of the big names in personality studies, claimed that introverts have higher levels of cortical arousal (stimulation and activity in the cortex) than extroverts.
3
One interpretation of this is that introverts don't require much stimulation. Extroverts, by contrast, want to be excited more often, and develop personalities around this.
Recent scanning studies, like those by Yasuyuki Taki and others,
4
suggest that individuals demonstrating neuroticism show smaller-than-average areas such as the dorsomedial prefrontal cortex and the left medial temporal lobe including the posterior hippocampus, with a bigger mid-cingulate gyrus. These regions are implicated in decision-making, learning and memory, suggesting a neurotic person is less able to control or suppress paranoid predictions and learn that these predictions are unreliable. Extroversion showed increased activity in the orbitofrontal cortex, which is linked to decision-making, so perhaps because of this raised activity in the decision-making regions, extroverts are compelled to be active and make decisions more often, leading to more outgoing behavior as a result?
There is also evidence to suggest there are genetic factors underlying personality. A 1996 study by Jang, Livesley and Vernon using nearly 300 pairs of twins (identical and non-identical) suggested that the heritability of the Big 5 personality traits ranged from between 40 percent to 60 percent.
5
What the preceding paragraphs boil down to is that there are some personality traits, specifically five, that have a large body of evidence behind them and appear to be associated with brain regions and genes. So what's the issue?
Firstly, many argue that the Big 5 personality traits don't provide a thorough description of the true complexity of personality. It's a good overall range, but what about humor? Or tendency to religion or superstition? Or temper? Critics suggest the Big 5 are more indicative of “outward” personality; all those traits can be observed by another person, whereas much of personality is internal (humor, beliefs, prejudices and so on), taking place largely inside your head and not necessarily being reflected in behavior.
We've
seen evidence that personality types are reflected in the configuration of the brain, suggesting they have biological origins. But the brain is flexible and changes in response to what it experiences, so the brain configurations we see could be a consequence of the personality types, not a cause. Being very neurotic or extroverted means you end up with distinct experiences, which could be what the arrangement of your brain bits is reflecting. This is assuming the data itself is 100 percent confirmed, which it isn't.
There's also the manner of how the Big 5 theory came about. It is based on factor analysis (discussed in
Chapter 4
) of data produced by decades of personality research. Many different analyzes by different people have found these five traits repeatedly, but what does this mean? Factor analysis just looks at the available data. Using factor analysis here is like putting several large buckets across town in order to collect rain. If one persistently fills up before the others, you can say the location of that bucket gets more rain than elsewhere. This is good to know, but it doesn't tell you
why
, or how rain forms, or the various other important aspects. It's useful information, but it's just the start of understanding, not the conclusion.
The Big-5 approach has been focused on here because it's the most widespread, but it's far from the only one. In the 1950s, Friedman and Rosenhan came up with Type-A and Type-B personalities,
6
with Type-As being competitive, achievement-seeking, impatient and aggressive, and Type-Bs not being these things. These personality types were linked to the workplace, as Type-As often end up in management or high-flying positions due to their characteristics, but a study found that Type-As were twice as likely to suffer from heart attacks or other cardiac ailments. Having a personality
type could literally kill you, which wasn't encouraging. But follow-up studies suggested this tendency towards heart failure was due to other factors, such as smoking, poor diet, the strain of screaming at subordinates every eight minutes and so on. This Type-A/Type-B approach to personality was found to be too generalized. A more subtle approach was needed, hence the more detailed interest in traits.
Much of the actual data that trait theories emerged from was based on linguistic analysis. Researchers including Sir Francis Galton in the 1800s and Raymond Cattell (the man behind fluid and crystallized intelligence) in the 1950s looked at the English language and assessed it for words that revealed personality traits. Words such as “nervous,” “anxious” and “paranoid” can all be used to describe neuroticism, whereas words such as “sociable,” “friendly” and “supportive” can apply to agreeableness. Theoretically, there can be only as many terms of this kind as there are personality traits to apply them toâthe so-called Lexical Hypothesis.
7
The descriptive words were all collated and crunched and the specific personality types emerged from it, and provided a lot of data for the formation of later theories.
There are problems with this approach too, primarily as it depends on language, something that varies between cultures and is constantly in flux. Other more skeptical types argue that approaches such as the trait theory are too restrictive to be truly representative of a personality: nobody behaves the same way in all contexts; the external situation matters. An extrovert may be outgoing and excitable, but if they're at a funeral or an important business meeting they wouldn't behave in an extroverted manner (unless they've got deep-seated issues), so they would handle each occasion
differently. This theory is known as situationism.
Despite all the scientific debate, personality tests are common.
Completing a quick quiz, and then being told you conform to a certain type, is a bit of fun. We feel we have a certain type of personality, and completing a test that says we do have this type validates our assumptions. It might be a free test on some poorly assembled website that keeps asking us to sign up for an online casino every six seconds, but a test is a test. The classic is the Rorschach test, where you look at an unspecified pattern of blobs and say what you see, such as “butterflies emerging from a cocoon,” or “the exploded head of my therapist who asked me too many questions.” While this might reveal something of an individual's personality, it isn't something that can be verified. A thousand very similar people could look at the same image and give a thousand different answers. Technically, this is a very accurate demonstration of the complexity and variability of personality, but it's not scientifically useful.
But it's not all frivolous. The most worrying and widespread use of personality tests is in the corporate world. You may be familiar with the Myers-Briggs Type Inventory (MBTI), one of the most popular personality-measuring tools in the world, worth millions of dollars. The trouble is, it is not supported or approved by the scientific community. It looks rigorous and sounds proper (it too relies on scales of traits, extrovertâintrovert being the most well-known one), but it's based on untested decades-old assumptions put together by enthusiastic amateurs, working from a single source.
8
Nonetheless, at some point it was seized on by business types who wanted to manage employees in the
most effective manner, and thus it became globally popular. It now has hundreds of thousands of proponents who swear by it. But then, so do horoscopes.
One explanation for this is the MBTI is relatively straightforward and easily understood, and allows sorting of employees into useful categories that help predict their behavior and manage them accordingly. You employ an introvert? Put her in a position where she can work alone and don't disturb her. Meanwhile, take the extroverts and put them in charge of publicity and engagement; they like that.