Transcript Evidence-Based Practice

PERSONALITY
AND HEALTH
Lecture 5
Yvette Lamb
Recap from last lecture
◦ Humourism (associated with early thinkers such as Hippocrates and
Galton) suggested that imbalances (“dyscrasia”) in the four humours
resulted in particular temperaments, along with poor health.
◦ Temperaments (sanguine, choleric, melancholic, phlegmatic) indicated
behavioural and emotional tendencies, along with disease
susceptibilities.
◦ Medicine aimed to restore the humours to a state of balance
(“eucrasia”) via techniques such as bloodletting.
Recap from last lecture
◦ Phrenology suggested that the source of personality was the brain,
with different character traits being located in specific areas of the
brain.
◦ Very popular in the first half of the 19th century before being
discredited as a scientific theory.
◦ We now know that complex forms of cognition are generally not
localised in this manner – instead involving the integration of
information from multiple, interconnected brain regions (e.g.,
Bressler, 2002).
PERSONALITY IN
POPULAR CULTURE
Astrology
Gender
◦ Masculine (Positive)
◦ Feminine (Negative)
Element
◦ Fire – Leo, Sagittarius, Aries
◦ Air – Gemini, Aquarius, Libra
◦ Earth – Virgo, Capricorn, Taurus
◦ Water – Scorpio, Pisces, Cancer
Astrology
Quality
◦ Cardinal – Cancer, Aries,
Capricorn, Libra
◦ Fixed – Scorpio, Leo, Taurus,
Aquarius
◦ Mutable – Pisces, Sagittarius,
Virgo, Gemini
Evidence for astrological
signs affecting personality?
◦ Studies have confirmed that, as astrology proposes, individuals
with positive sun signs (Aries, Gemini, Leo, Libra, Sagittarius
and Aquarius) are extraverted and individuals with negative sun
signs (Taurus, Cancer, Virgo, Scorpio, Capricorn and Pisces) are
introverted (Mayo, White & Eysenck, 1978; van Rooij, 1994).
◦Why might this be the case? Are the positions of stars affecting
our personality or is there more to it? Think critically!
J. K. Rowling’s Hogwarts
“Now each of these four founders
Formed their own house, for each
Did value different virtues
In the ones they had to teach.
By Gryffindor, the bravest were
Prized far beyond the rest;
For Ravenclaw, the cleverest
Would always be the best;
For Hufflepuff, hard workers were
Most worthy of admission;
And power-hungry Slytherin
Loved those of great ambition.”
Veronica Roth’s Divergent Factions
MODERN
PERSONALITY
THEORIES
Trait theories
◦ Personality theorists such as Freud and Jung relied heavily
on their own intuition when formulating their ideas. Working
in a clinical setting, they observed the behaviour of their
clients and theorised that particular personality structures
were guiding behaviour.
◦ The trait theorist, in contrast, relies on objective statistical
procedures to identify personality structures and to measure
these.
Group work: Creating a scientific theory
of personality
◦ Today we will be working through a series of steps the trait theorists
followed in their attempts to a simple and coherent taxonomy of
personality.
◦ As a starting point, we want to capture the personality traits that
everyday people consider important in describing personality.
Group Challenge 1: How do we know what personality traits
might be relevant to a particular population?
Group work: Creating a scientific theory
of personality (1)
◦ The fundamental lexical (language) hypothesis
“the most important individual differences in human transactions
will come to be encoded as single terms in some or all of the
world’s languages” (Goldberg, 1990, p.1216)
We have developed single words/terms that allow us to easily describe the
individual differences in personality that we have considered important enough to
note.
E.g., in survival, it might have been important to be able to share with Person A
how reliable or treacherous Person B is.
Group work: Creating a scientific theory
of personality (1)
◦ The fundamental lexical (language) hypothesis
“the most important individual differences in human transactions
will come to be encoded as single terms in some or all of the
world’s languages” (Goldberg, 1990, p.1216)
Using this technique, Allport and Odbert (1936) identified around 18,000
personality-related words in an unabridged English dictionary. Around 4,500 of
these words were consistent with the definition of a personality trait (indicating a
relatively consistent tendency that is generalised and personalised).
Group work: Creating a scientific theory
of personality
◦ The goal is to identify a set of basic, universal traits - but as you can
see from Allport and Odbert’s research, we have a very long list of
traits that may be on this list!
Group Challenge 2: How can we identify a set of basic traits that
is both simple and comprehensive?
Group work: Creating a scientific theory
of personality (2)
◦ Some traits tend to co-occur in individuals – they appear alongside
one another.
◦ Think about the ways in which we might describe a human body. We
might specify the length of your head, the length of your neck, the
length of your torso, the length of your arms, the length of your legs
etc.
◦ How might we summarise these lengths?
These specific lengths tend to be closely related to each other
and can be seen as manifestations of your overall height.
Correlations
◦ A correlation is a number that tells us the degree to which two
variables go together.
Group work: Creating a scientific theory
of personality (2)
◦ Similarly, certain personality traits co-occur.
◦ The statistical technique of factor analysis has provided trait
theorists with a tool to summarise how a large number of variables
co-occur. By looking at patterns within a mass of correlations, factor
analysis can tell us how many underlying factors are necessary to
summarise these variables.
◦ Psychological names might then be assigned to these underlying
factors. These factors are considered the structure of personality.
Factor Analysis
◦ Factor analysis tells us which traits co-vary, but does not tell us why
they do so. Some theorists, for example, believe that reward sensitivity
is at the core of extraversion (e.g., Lucas et al., 2000), while others
believe social attention is (Ashton, Lee, & Paunonem, 2002).
◦ Theorists also differ on how many factors they include in their
personality models, as there is subjectivity involved in interpreting the
analysis. Most frequently, five factors have been identified. These are
referred to as the Big Five personality traits.
The Big Five Traits
Openness
Conscientiousness
Extraversion
Agreeableness
Neuroticism
The Big Five Traits
◦ McCrae and Costa (1997) claim that the Big Five personality
model is universal, although this is a somewhat contentious
issue.
◦ A well-developed and commonly used personality
questionnaire is the NEO-Personality Inventory Revised
(NEO-PI-R; Costa & McCrae, 1992).
Is the Big Five a useful model?
◦ It is important for trait theorists to consider whether their
personality classifications are of practical value. Traits may
affect our everyday behaviour and allow us to make
predictions (e.g., predicting job performance in those
applying for work).
◦ Reading for this week! Ozer and Benet-Martinez (2006) –
Personality and the prediction of consequential outcomes.
NEUROSCIENCE OF
PERSONALITY
Personality Neuroscience
◦ Interactions between our genes and environment must be
affecting our brain in some sort of lasting way.
◦ DeYoung and colleagues (2010) examined the biological
bases of the Big Five personality traits
MRI images from De Young et al., (2010)
PERSONALITY AND
LONGEVITY
The Nun Study
◦ Nuns living in the US and born in
1917
◦ In 1930, they were asked to write
an autobiography.
◦ Researchers read these
autobiographies and examined the
amount of positive emotions that
the nuns expressed in their writing.
The Nun Study
Some of the autobiographies
contained a high level of positive
emotion.
“the past year … has been a very happy one.
Now I look forward with eager joy …”
The Nun Study
Some of the autobiographies
contained a relatively low level of
positive emotion.
“ I intend to do the best for our order; for the
spread of religion and for my personal
sanctification”
Quotes from Danner et al, 2001 (pg. 806)
The Nun Study
The study revealed a positive
relationship between positive emotions
and length of life.
Nuns who had expressed more positive
emotions in their 1930’s
autobiographies lived longer.
Danner, Snowdon & Friesen, 2001
The Nun Study
◦ Why were nuns considered
ideal research subjects?
Consider their environment.
◦ What are some of the possible
limitations of this research?
The Nun Study
◦ Friedman (1999) found no association between
cheerfulness and longevity - but this may be due to risktaking and substance abuse in these cheerful individuals.
◦ Other longitudinal studies have indicated an association
between optimism and longevity (Maruta et al., 2000;
Peterson et al., 1998).