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PERSONALITY
AND HEALTH
WHAT IS PERSONALITY?
Lecture 4
Yvette Lamb
What is Personality?
Personality is a term used to refer to
“psychological qualities that contribute
to an individual’s enduring and
distinctive patterns of feeling, thinking
and behaving”
(Cervone & Pervin, 2010)
WHAT FACTORS
INFLUENCE PERSONALITY
DEVELOPMENT?
Environmental influences on personality
Environmental influences on personality
◦ Culture – E.g., collectivist versus individualist cultures
◦ Family – E.g., birth order effects
“I am” statements (Bochner, 1994)
(Paulhus, Trapnel, & Chen,1999;
Healey & Ellis, 2006) and first born
preference (Keller & Zach, 2002)
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Environmental influences on personality
Genetic influences on personality
◦ Peers – E.g., quality of friendships
◦ Behavioural genetics is the study of genetic
(Berndt, 2002)
Genetic influences on personality
contributions to behaviour. Twin studies, adoption
studies and selective breeding studies are common
research methods.
◦ Heritability estimates for personality are around .40
(Cervone & Pervin, 2010)
Genetic influences on personality
◦ Heritability refers to the proportion of phenotypic
variation in a population that is attributable to genetic
differences
Genetic influences on personality
Genetic influences on personality
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Genetic influences on personality
https://www.youtube.com/watch?v=IyT2AlzzzQ
s
Meet Jim Springer and Jim Lewis
◦ Identical twins separated at birth
◦ Both named John and known as
Jim
◦ Did not meet until they were 39
years old (after having spent 39
years apart)
Meet Jim Springer and Jim Lewis
When they finally met, they found out…
◦ Both liked beer and were chain smokers
◦ Both did woodwork in their garages and
drove Chevrolets
◦ Both served as sheriff ’s deputies
◦ During childhood, they had each owned
a pet dog named ‘Toy’
◦ Both had married twice – initially
marrying women named ‘Linda’ and
then women named ‘Betty’
◦ Both had a son named ‘James Allen’
What might explain these similarities??
Nature via nurture
◦ Remember that
development from genes
occurs in an
environmental context
◦ Interactions between
genes and environment
can be complex
Nature via nurture
E.g., Kim-Cohen and
colleagues (2006) found geneenvironment interaction in
which variation the MAOA
gene moderates the
relationship between
exposure to physical abuse
and the development of
mental health problems.
THEORIES OF
PERSONALITY
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The Four Humours
PERSONALITY AND
MEDICINE IN
ANCIENT GREECE
The Four Humours
“When these four humours are
properly mingled the body is in
a state of health; when there is a
defect or an irregularity in the
mixture, disease arises.”
Castiglioni, 1941
◦ Hippocrates – variations in personality
reflect variations in bodily fluids
◦ Ancient Greek belief that all of nature
was composed of fire, earth, water and
air (the four elements)
◦ In the human body, these elements are
represented by the four humours
(yellow bile, black bile, phlegm and
blood)
The Four Humours
◦ Yellow bile comes from the liver
(ulcers)
◦ Black bile comes from spleen and
stomach (tumours)
◦ Phlegm comes from the brain
(watery swelling)
◦ Blood comes from the heart
(inflammation)
The Four Humours
◦ Yellow bile = choleric
temperament
◦ Black bile = melancholic
temperament
◦ Phlegm = phlegmatic
temperament
◦ Blood = sanguine temperament
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The Four Humours
◦ Similar ideas about bodily fluids
and temperament persisted up until
the 20th century
◦ Early theories of
temperament
have had an
enduring impact
on models of
personality, e.g.,
Smalley & Trent,
2005
Phrenology
◦ Emerged in the 19th Century
◦ By the 19th Century, most
theorists considered the brain
to be the source of personality.
◦ Gall (1835) – specific locations
of personality traits in the
brain.
◦ Gall claimed the size of the
skull in a certain region reveals
the size of brain area beneath
it.
Picture from Severn (c. 1920), Figures from Vaught (c. 1902)
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