The Big 5 Personality Traits – psychobabble or science?

Alice Friedemann’s review of :

Daniel Nettle.  2008.  “Personality, What makes you the way you are”.  Oxford University Press.

Scientists have considered psychology to be a very soft science at best and quackery or psychobabble at worst.  But psychology is finally making scientific strides with the testable theories generated by evolutionary biology, brain imaging equipment, being able to measure genetic variation between people, and animal studies – critters also exhibit what in humans we call personality traits.

Daniel Nettle has written a book for the public explaining the latest scientific research on personality.  He explains how it’s measured, what the measures mean or predict, and why we vary in personality traits.

He defines personality as:

  • Consistent patterns in our lives across love, career, and friendships, often repeating the same sorts of triumphs or mistakes.
  • Even smaller, less significant patterns in everyday life tend to have patterns – how we dress, whether we talk to strangers, etc
  • Basically, everyone’s nervous system is wired up differently.

Nearly all psychologists agree on a Big Five model of personality dimensions, consolidating decades of research.  Before this, different researchers used different varying traits.  For example, 4 main types (thinking, feeling, sensing, or intuiting), or just reward vs harm avoidance. Each study had results that appeared to have no relationship to each other.

The five factor model created order out of this mess, all previous studies can be fit into this framework because they either measured one of the big five or a sub-part of one of them, or perhaps a mix of several.

Okay, it’s not science entirely yet – to do that, this new approach needs to prove these traits are neurobiologically real, but this framework gives personality psychologists testable hypotheses.  Until now, much of it sounded like psychobabble to me, and I do cringe at lumping people into categories.

What makes the big 5 more plausible to me is that we all have all five traits to varying degrees, and we change over time depending on our genetics and our life experiences (which is why twins, even though totally the same genetically, can be quite different).

Here’s the list of the Big 5:

Dimension                   High Scorers are                    Low Scorers are

Extraversion                Outgoing, enthusiastic            Aloof, quiet

Neuroticism                 Prone to stress & worry         Emotionally stable

Conscientiousness       Organized, self-directed         Spontaneous, careless

Agreeableness              Trusting, empathetic              Uncooperative, hostile

Openness                     Creative, imaginative             Practical, conventional

About half of your score is out of your control – genetics is responsible.

These traits have important consequences in life. High neuroticism in either partner is more likely to lead to divorce or an unhappy marriage.  Divorce is also likely if the male is low in conscientiousness.  Extraverts are the least likely to stay in an unhappy marriage.

Other consequences, such as low agreeableness, have less dire consequences, but will nevertheless affect how a person gets along in the world.  These folks are more likely to snap at others and be irritated easily, leading to less satisfying personal relationships and career advancement.

Situations make a difference, extraverts have more casual sex than introverts, probably because introverts are at home and extraverts are at parties, meeting potential partners.

A recurring theme of the book is that while you might think that there’s some optimum level of any trait to have, this doesn’t appear to be the case or natural selection would make us much more similar.  For example, high scoring neurotics are more worried than other people.  Why not just be happy all the time?

Nettle says that animals vary in what we could call neuroticism too – some guppies hide if there’s a predatory fish in the tank because they come from a stream with predators, and other guppies are fearless because they live in a place with no predatory fish.  The fearful guppies outlive the fearless guppies by far if you introduce a predator.

But creatures who spend too much time looking for predators won’t get enough to eat and be as healthy as their more relaxed brethren – so there’s a constant balancing act going on in nature across neuroticism and all of the other traits.  In one situation a trait might be good, in another bad, and so there is never an optimal balance of a particular trait that nature settles on (in evolutionary theory this is called fluctuating selection).


Extraverts are high in sociability but that doesn’t mean they have good social relationships – that’s predicted by agreeableness.  Shyness isn’t usually due to low extraversion, but to high neuroticism and anxiety.  Someone low on extraversion can do without much social activity and not mind it, often seeming aloof.

Extravert traits: enjoy sex, romance, tend to be ambitious, work hard for fame or money, like active sports, travel, and novelty. They have a lot of positive emotion, with more joy, desire, enthusiasm, and excitement than low scorers.  This acts as an incentive, so they’re more willing to go the extra mile to a party, event, or date after an exhausting day at work.  This doesn’t mean low scorers on the extrovert scale are negative or sad, they’re just emotionally flatter, which makes them less likely to get out and about, because there’s less reward in it for them.

Extraverts brains even operate differently – with higher responsiveness in several brain areas than low scorers.

Nettle speculates at the end of each chapter about the advantages and disadvantages of each trait.  So who wouldn’t want to be an extrovert?  Nettle says that perhaps their predilection for dangerous sports leads to earlier deaths, and more breakups of marriages from affairs, which puts their children at risk with step-parents.

Within a marriage, if your partner is a higher scorer than you, they’ll want to do things that seem pointless and expensive whether it’s buying a sports car, wanting to go to far more parties than you do, or taking up a wild new hobby.  If you score higher, then you’ll feel disappointed (s)he doesn’t want to do as much as you do or get enthusiastic about your latest passion.  Nettle concludes “Don’t worry. It’s just how they are wired up”.


Scoring high means being more affected by the tribulations of everyday life, feeling more fear, anxiety, shame, guilt and sadness than most people. Neurotics are more likely to have depression, anxiety, eating, personality, and obsessive-compulsive disorders, phobias, PTSD, schizophrenia, insomnia, and headaches.

Sadness may be useful — to the extent it slows us down enough to re-think our plans if they’ve failed, and make better plans for the future, and signal to others we need support and comfort.

Why on earth would such an unhappy trait be selected for? We’re probably all wired to look for dangerous predators, loss of social position, or the risk of social ostracism – death sentences for most of our ancestors.   But Nettle says that neurotics are like overly sensitive smoke detectors, spending a lot of time looking for dangers.   Chances are the ancestors of neurotics worried a lot, but in the end, were less likely to make a fatal error than their happier brethren, and avoided being eaten or making the leaders of the tribe angry and being expelled from the group.

High scorers tend to direct their negative emotions towards themselves, leading to low self-esteem. Neurotics think ‘it was my fault’, everybody hates me’, or ’I will never succeed’ in reaction to bad events.  A high scorer is constantly wondering if (s)he did the right thing and often changes their identity and goals throughout life.

High scorers fear dangers faced in the past – rejection, illness, open spaces, strangers, and unspoken negative intentions of others.  In the long run they have a slightly increased risk for heart disease, gastric disorders, and hypertension.  They have less satisfactory marriages and work lives. Their negative emotions can bring about the very result they fear, such as a wife who worries and nags her husband due to her fear he’ll leave may give him reason to do just that.

Nettle posits this trait is selected for to protect us, and the threshold of what’s appropriate to worry about is constantly changing depending on what sort of world we’re born into.  Perhaps those who score low have a higher mortality rate because they’re not worried enough.

Although this trait usually harms careers, a neurotic open person might write as a form of therapy.  Their fear of failing motivates them to strive (as long as they aren’t too disorganized or feel too awful to function). Nettle writes that neurotics “see the problems of the world starkly, in all their equivocal complexity”.

He concludes “High scorers should not just wish their worry away, but, just like any other trait, understand the strength, sensitivity, striving, and insight that it may give them. There are niches in the world where these are very valuable.  They do come at a cost of often awful suffering through many days of their lives. The art is to manage these costs, to live with them, and to limit them so they do not become overwhelming”.


High scorers are conscientious and high scores predict better than any other trait occupational success in any kind of work, as well as living longer – up to 30% more than someone who scores low.

Low scorers have impulse control problems and are more likely to succumb to one or more of gambling, drug dependencies, irresponsible behavior, law breaking, and antisocial personality disorder.  They’re more impulsive, spontaneous, and have weak wills.  A low score in this trait is the most likely predictor of addiction problems.

Addictions happen when a person can’t stop a once-rewarding behavior.  There may be no euphoria involved, because their brains have become so used to the addictive substance.  They just can’t stop their habit.


Agreeable people can sort out complex descriptions of how people are feeling.  Nettle gives these two examples:

Tom hoped that Jim would believe that Susan thought that Edward wanted to marry Jenny (4th level nested description).

John though that Penny thought that Tom wanted Penny to find out whether Sheila believed that John knew what Susan wanted to do (5th level nested description).

It turns out that people who do best at understanding the last sentence tend to have a larger network of friends than those who don’t do well. Young children with this skill are perceived by their teachers as getting along well with other kids.

Empathizers pay more attention to the mental states of others and tend to be helpful, social, warm trusting behavior.  They tend to have good relationships, good social support, and rarely fall out with or insult others.  They’re quick to forgive, and slow to anger even with people who deserve it.  Often they end up in careers as counselors, social workers, or volunteer work.

Those who score low are less likely to trust or help others, can be cold or antagonistic, have less harmonious relationships, and at the very bottom, psychopathy.

Psychopaths are egocentric, dishonest, feel no remorse, can’t love, and tend to use others for their own ends.  They have no qualms about being aggressive.  Of the three traits, empathy for others is the most important in preventing psychopathy.

But to be a full-blown monster, you’d also need to score low on conscientiousness and anxiety.  Without empathy, the person still might not do harm because they’re not impulsive and will realize the likely consequences of their actions.  If he’s also low in neuroticism, he’ll feel no fear – now all the barriers are down and this can result in some very bad people.  Fortunately it’s rare for someone to be very low across all three traits.

Autistics are not psychopaths.  Although they have trouble with social relationships, and struggle to understand the mental state of others, they tend to be helpful to others in distress.  Psychopaths can predict others mental states just fine and use that knowledge to manipulate and deceive.

Nettle speculates that being a good group member is a very important trait – being ostracized from the group in the past could be a death sentence.

He doesn’t discuss why psychopathy would exist, but I’ve read elsewhere that psychopaths are the only people unafraid in battle, and our history is one of constant skirmishes, so this trait would be useful throughout most of history if these people were channeled into the military.

Being too agreeable tends to lessen success a bit, since you’re spending more time than average maintaining a wide network of relationships, which takes time away from work, or lessens the ambition to rise in a career since that isn’t as important as friendships.  Nettle refers to two studies that showed nice guys finish last. Some ruthlessness is required to reach the highest positions in corporations perhaps.

Which brings up the conundrum of finding an ideal partner – women would like someone who’s kind and empathic, but also someone successful – and these traits don’t usually coincide. As Nettle puts it “the kind of person who could give you a glittering lifestyle is quite likely not the kind of person you would wish to share such a life with”.

One of the most documented and proven differences between men and women score higher in Agreeableness than men – the average man scores lower than 70% of women.   When women are given testosterone, it reduces their empathetic behavior.


High scorers are more likely to read books, and go to art galleries, theater, and music events than the average person.  This trait is correlated with intelligence, but it’s not the same as intelligence.  People who score high tend to be imaginative and pursue artistic endeavors.

In several pages of writing about Ginsberg’s poem “Howl”, Nettle conveys the trait of openness with a bit of poetry himself.  He thinks that those who score high in openness have fewer, more permeable filters that allow broader associations.  Those high in openness are more likely to challenge social norms, try out many different jobs, philosophies, and lifestyles.  They also have a strong sense of spirituality, or even supernatural belief.

Often they have a schizotype personality – they’re of sound mind but more psychotic than the rest of the population.  They might hear voices, have perceptual disturbances where everything seems strange or significant, magical ideas (supernatural forces, feelings of telepathy).  Or they might have unusual experiences and aberrant thoughts and even some beliefs similar to those of schizophrenics, but not have other aspects of schizophrenia like emotional flatness or social withdrawal and lack of motivation. High-scorers are more likely to have psychosis-like experiences.  They tend to be politically liberal and avoid orthodox institutions, with strong idiosyncratic supernatural or spiritual beliefs.  They’re more likely to experiment with exotic religions or creeds, New Age ideas, or believe in the paranormal.  They’re more likely to have beliefs that run against the mores of their time and less governed by taboos or social acceptability.   They’re relatively susceptible to hypnosis.

Advantages: “Geoffrey Miller argued in his book, “The Mating Mind”, that verbal creativity became a potent mate-selection trait.  …Individuals would tend to select mates displaying the quality of their brains through unusually complex verbal and symbolic” ways of writing or speaking, driving up general intelligence in the population, as well as openness.

How we come to have our personalities

Except for genetics, studies with identical twins, fraternal twins, and siblings have shown that parents have very little effect on our personalities.  In normal households that is, clearly an abusive or violent upbringing might have lasting effects.

“This is a stunning finding, and it has caused quite a stir.  It is probably the most important discovery in psychology in recent decades, not least because it is counter-intuitive and overturns many entrenched beliefs.  Out must go all simple notions about how cold mothers or absent fathers or large families or farm living shape our personalities”.

Then he knocks out birth order and prenatal effects.

The main thing that seems to make a difference is your own traits:

“The extent to which one should be neurotic about sources of harm depends in part on how fleet of foot one is, how good one’s immune system is, etc.  Whether one should pursue risky rewards depends a lot on whether one is strong and attractive.  The former makes one able to cope if things go wrong, whilst the latter is a big determinant of success if the rewards pursued are social or sexual ones.  Whether one needs to be very conscientious in working hard at problems depends in part how smart one is; very quick-witted people can probably prepare on the fly.  Basically, it makes a lot of sense that evolution would have built into us a capacity to modulate our personalities in response to our health, intelligence, size, and attractiveness”.

There is some evidence for this – extraverts are more symmetrical, implying fewer mutations or environmental stressors during development, and they’re perceived as being more attractive.  Men increase in extraversion when they’re tall, though this isn’t the case with women.  Large men also seem to be slightly less nice, on average, perhaps because large men can get away wit breaking rules.


All of us vary in each of the 5 dimensions, just like we do with weight, height, or intelligence. Nettle posits that if we could measure people with ten distinct points along each of the five personality scales, there’d be 105, or 100,000 possible personalities. So even though life would be much simpler if we could wedge everyone into a few categories, we’d be wearing blinders to the true complexity of our fellow human beings.

If you took the 100,000 personalities literally, there’d be 1,500 other women just like me in the USA.  But they won’t be like me.

Nettle speculates that though they’ll have more similar lives and relationships than a random sample, their lives will be very different because they’ve all found different ways of expressing the traits they have.  There are many ways of expressing extroversion.

Even more importantly, there’s the level of one’s subjective life story.  We all tell our story of who we are, what we’re doing, and why differently in our personal stories.  This unique narration has a considerable effect on identity.   Nettle gives the examples of someone who never married could either tell this story as a tragedy or a comedy.  Another who was never successful in a career, but had great varied experiences could either tell their story as one of failure or how they’d escaped the rat race and had a much better time.

Which brings up the topic of change – what if we don’t want to be shy worried irresponsible hostile conformists?

Luckily, as we age, all of us tend to get slightly more agreeable and conscientious, and slightly less open, extroverted, and neurotic.  We have the power to change ourselves, to stop destructive or dangerous behaviors.

It’s easier when the changes we try to make go along with our nature, like an extrovert switching from riding a motorcycle to driving a sports car. But even an introverted person can change themselves against the grain, by finding work or social activities that involve being around lots of people.

And above all, we can spin our own personal stories to see our lives in a better light.

Alas, Nettle says, those who most need to do this – those high in neuroticism — have the hardest time seeing their lives in anything but a negative light (though they’re more realistic than low scorers).  Those most likely to be unhappy about their personalities tend to neurotics who infuse everything with suffering.  He recommends neurotics try meditation, exercise, yoga, cognitive behavior therapy, and medications to work around their fears and anxieties.

Nettle concludes by reminding the reader that no one should regret the constellation of personality traits they have – all have their advantages and disadvantages, which he has illustrated throughout the book.   Though these speculations about why a trait might be good or bad given different environments is the least scientific part of the book – but then there’s still much to be learned, and we can hope this new grouping of traits will lead to better testing.

I was not able to tell from reading the book if this new “big 5” concept was a major revolutionary shift within the personality field and adopted by the vast majority of researchers.  Wikipedia says that “The model is considered to be the most comprehensive empirical or data-driven enquiry into personality”.

Wikipedia gives these main criticisms:

1)      This is not a theory, just data-driven descriptions of traits

2)      Not all traits are included (i.e. Religiosity, Honesty, Thriftiness, Conservativeness,  Sense of humor, etc)

3)      There are 3, or 18, or 7 factors, not 5

So it looks like personality research has a long way to go to reach more scientific credibility.

But overall, this book was useful and fun to read.  Nettle describes quite well what it’s like to be weak or strong in these dimensions, and I recognized myself and so many others in the descriptions – it’s somehow satisfying to know that I share these traits, both good and bad, with so many others, and to have another tool to understand others with.

I also liked Nettle strongly emphasizing throughout the book that there is no best profile to have, not even being average in all of them.  Your best bet is to make the best of the hand you’ve been dealt – maximize your strengths and minimize your weaknesses.  Your basic dispositions are a resource, not a curse.

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