PSYB30H3 Lecture Notes - Lecture 4: Personality Development, Twin Study, Takers
PSYB30 - Introduction to Personality
Lecture 4 - Personality Development
Personality Development
Thinking About Personality Development
● Has your own personality ever changed? Is it changing now? Why or why not?
○ Situational
○ Societal pressures
○ Cultural differences
○ Individual differences
What Happens to Personality Across Development?
● Are traits stable as we develop or do they change?
○ Do not change across different states
● Is an issue of stability
● Several ways that stability can be studied
Three Levels of Analysis
● Population Level
○ Changes or constancies that apply more or less to everybody
■ Sexual interest increases at puberty for almost everyone
■ Impulsiveness decreases with age
● Group Differences Level
○ Changes or constancies that affect different groups differently (sex differences;
cultural or ethnic group differences)
■ Male teenagers are higher risk takers than females
■ White women more at risk for eating disorders
● Individual Difference Level
○ E.g., can we predict who is at risk for psychological disturbances later in life
based in earlier measures of personality?
How Do We Come To Have The Personalities That We Do?
● Long thought to be due to parenting and family influences
● Examples
○ Parents that read to their children
○ Parents that are violent and aggressive in punishments have children that are
aggressive
Role of Parenting
● Most effects are correlational
● Fail to recognize that parents also share same genes as children
● Twin studies have addressed this problem
○ Genetics
Twin Studies
● MZ twins and DZ twins
● Suggests heritability estimates of .5 of personality traits
● Shared environment = what siblings share, parenting practices, neighbourhood, family
life
○ Experiences are common in twins raised in the same household
● Nonshared environment is everything else. More important than shared environment
Personality Stability Over Time
● Stability of temperaments during infancy
○ Temperament
■ Individual differences that emerge very early in life, are heritable, and
involved behaviours are linked with emotionality
● A child may be cool and collected while another may be more
troublesome
■ As assessed by caregivers, temperament factors include activity level,
smiling and laughter, fear, distress to limitations, soothability, and the
duration of orienting
● Caregivers perception is through experience
● Rank order stability in adulthood
○ Across different self-report measures of personality, conducted by different
investigators, over differing time intervals (3 to 30 years), broad personality traits
show moderate to high levels of stability
○ Average correlations across traits, scales, and time intervals is about +.65 (fairly
strong correlation)
■ Slightly biased because it is self-report data
○ Stability also found using spouse-report and peer-report
○ Personality consistency tends to increase in stepwise fashion with increasing age
- personality appears to become more and more “set in plaster” with age
● Mean level stability in adulthood
○ “Big five” personality factors show a consistent mean level stability over time
○ Especially after 50, very little change in the average level
○ Small but consistent changes, especially during the 20s
■ Openness, extraversion, neuroticism decline with age until 50
■ Conscientiousness and agreeableness show gradual increase with time
Research Points To The Following Conclusions
● Stable individual differences emerge early in life, where they can be assessed by
observers
● For most temperament variables, there are moderate levels of stability over time during
the first year of life
Document Summary
Several ways that stability can be studied. Changes or constancies that apply more or less to everybody. Sexual interest increases at puberty for almost everyone. Changes or constancies that affect different groups differently (sex differences; cultural or ethnic group differences) Male teenagers are higher risk takers than females. White women more at risk for eating disorders. Long thought to be due to parenting and family influences. Parents that are violent and aggressive in punishments have children that are aggressive. Fail to recognize that parents also share same genes as children. Suggests heritability estimates of . 5 of personality traits. Shared environment = what siblings share, parenting practices, neighbourhood, family life. Experiences are common in twins raised in the same household. Individual differences that emerge very early in life, are heritable, and involved behaviours are linked with emotionality. A child may be cool and collected while another may be more troublesome.
