Personality - Notes

Detailed examination of the 5 key facets of personality; Openness, conscientiousness, extraversion, agreeableness and neuroticism. Everyone has all of these factors like we all have height and weight but the degree varies with each individual.

These 5 facets represent the consensus research view of what constitutes personality and in individuals these facets are stable over long periods of time. Each of the 5 should be thought of as a variation in some underlying brain circuit which affects a family of related psychological functions.

‘Personality traits are meaningful, stable, partly genetically inherited consistencies in classes of behaviour. They affect our response to life events but also which life events we are going to have. They can be measured using ratings and are predictive when aggregated over many instances.’

Traits cant be observed directly they can only be inferred from a person’s behaviour.

‘Trait statements entail predictions about neurobiological and perhaps even genetic differences between people.’

Initial section on how research and statistics have defined these dimensions of personality, correlations are explained in order to highlight the degree of causal relationship between 2 variables. A correlation coefficient of 1 means that varying the 1st quantity perfectly predicts how the 2nd will behave, a coefficient of zero at the other end of the spectrum gives no information.

The traffic between personality and behaviour goes both ways – (Situation selection) behaviour creates more situations, eg extraverts have more casual sex than others. They talk to others more easily and go to more parties – ‘a party is essentially a device for allowing extraverts to find each other’. A set of choices that make certain situations more likely to occur.


Care should be taken when associating extraversion with sociability. Shyness is due to high neuroticism and anxiety rather than low extraversion.

Extraverts have a lot of positive emotion. High extraversion scorers consistently report more states of joy, desire, enthusiasm and excitement than low scorers.

‘Extraversion is variation in the response to positive emotion. High scorers are prepared to work hard to get the buzz of company, excitement, achievement, adulation and romance. Low scorer’s positive emotion systems are less responsive so the psychological benefits of getting these things are fewer. Given the cost of getting them the introvert is less motivate.’

‘In humans the physiological response to a drug that has dopamine like effects in the mid-brain is linearly related to extraversion scores. There is converging evidence that what makes an extravert is a high degree of responsiveness in a suite of dopamine driven brain areas including the ventral tegmental, the nucleus accumbens and their projections.’

Book looks consistently at the evolutionary rewards and the likely environments which have tended to select for aspects of personality. The range in personality reflects the fact that no 1 type of personality will ever be perfectly optimized for all situations and environments. We are better as teams with a spread of differing personalities that will have strengths and weaknesses depending on the specifics of a situation. As with all dimensions of personality there is no right or wrong level.


Neuroticism appears to be a meaure of responsiveness to negative emotions. These include fear, anxiety, shame, guilt, disgust and sadness.

If positive emotions are designed to make us locate and go towards things negative emotions are designed to make us detect and avoid things. They operate on a smoke-detector principle and can go wrong therefore in 2 ways. Too sensitive and you get a false positive, a fire alarm when there is no fire. Not sensitive enough and you get a false negative no alarm when there is a fire.

The amygdala is more sensitive in high neuroticism scorers both to negative stimuli and at baseline. Serotonin also appears to be integral to the functioning of the regulatory circuit for negative emotions.

Depression is periodic, often reactive flare up to the effects of an underlying personality trait. This is a point at which negative emotions become so aroused that they self-perpetuate.


Conscientiousness relates to impulse control. High scorers are disciplined, organized, and self-controlled. Low scorers are impulsive, spontaneous and weak willed.

‘Conscientiousness is the magnitude of reactivity to those mechanisms in the frontal lobe that serve to inhibit an immediate response in favour of a goal or rule.’

‘Very low Conscientiousness means an addictive personality that cant stop doing things even when they are damaging.’

Conscientiousness is the most reliable personality predictor of occupational success across the board.’ In general the higher the score for Conscientiousness the better you will do all else being equal. The correlation is about 0.2 which is not that strong and shows many other influencing factors.


We are pro social animals. The regard for others behaviour can broadly be described as a series of mental mechanisms know as ‘theory of mind’. It allows us to represent the mental state of another.

Theory of mind consists of 2 capacities. Mentalizing is what we do when we attribute a mental state such as belief or an attitude to another. This is a learned and not an innate capacity. 2nd aspect is empathizing. This is also about representing the mental state of another but is specifically about their emotion and implies you are affected by that emotion.

High scorers for agreeableness are described as cooperative, trusting and empathetic . Low scorers are cold hearted hostile and non-compliant. ‘Being a high in agreeableness pre-disposes you to pay attention to the mental state of others and crucially to factor these into behavioural choices.’ This seems to create moral pleasure in helping and doing good for others.

A psychopath is at the extreme end for low-agreeableness. ‘Such individuals are completely egocentric, remorseless, dishonest, incapable of love and disposed to use others entirely to their own ends.’

Studies of personality and career success have frequently found that agreeableness is a negative predictor for career (corporate?) success – nice guys finish last. Leads to the familiar observation that many organizations and businesses are led by people with psychopathic tendencies.

One of the most robust sex differences in personality research is the finding that women are higher in agreeableness than men are. The difference is over half a standard deviation, which means that although there is plenty of overlap between the sexes, the average man scores lower than 70 per cent of women.

Fight or flight response tends to be a typical male response. The female response is better described as tend and befriend. (See work of psychologist Shelly Taylor).

Sex difference in agreeableness puts a different light on the debate on sex discrimination in society. ‘In general fewer women want to emphasise status gain at the expense of social connectedness. Given this in a market blind to gender you would still not expect to see a 50:50 distribution of top executives for example.


Openness correlates with some aspects of IQ and intelligence but is specially associated with a flair for and production of imaginative and creative endeavours.

Divergent thinking tasks show up the range of available mental associations. ‘Artists are people who in virtue of broad mental associations can produce the most arresting and attention grabbing representations.’

A significant part of all these 5 personality traits is rooted in genetics and heritability but by no means all.

Outside of genetics parental personality has no measurable impact on child personality.

‘What studies really show is that across a range of normal family-to-family variation, shared family factors have no effect on adult personality’

This is a stunning find – ‘it is probably the most important discovery in psychology in recent decades, not least because it is counter-intuitive and overturns many entrenched beliefs’.

‘There is no really compelling evidence for the importance of birth order in shaping personality.’

5 factor personality traits plus intelligence are the best statistical predictors of life outcomes but this does not eliminate responsibility or the capacity for development change and growth.

There are several levels of specificity:

  • 1st level are the 5 personality trait scores that are largely fixed by early biological mechanisms.
  • At the 2nd level we see characteristic behaviour patterns. They follow from the big 5 but are non specific. Eg what you choose to do for a living or how you spend your free time.
  • 3rd level is the most idiosyncratic and can be described as your personal life story. We are narrative creatures who tell a story about ourselves – in effect made up of our personal beliefs.

At the 1st level little change is possible

At the 2nd level with characteristic behaviour patterns more change is possible.

At the 3rd level our subjective life story is rather weakly constrained by temperamental factors of objective facts. If you have little money if you interpret this as a virtue or a failure is up to you. Reframing at this level is very important in psychotherapy and personal growth. High neuroticism is a constraint here not just because they tend to have a lot of bad things happen to them but because they struggle to tell positive stories about themselves. Those most in need of being able to tell a good story about themselves are the very people who find this most difficult to do.