Personality and Individual Differences
- How can personality be measured?
- What are the “basic” personality characteristics?
o Are there basic personalities?
- How (and how much) does personality change across the lifespan?
o At different point in life, do people’s characteristics tend to change
- How do hormones and brain chemicals relate to personality?
o How do synapses and neurotransmitters affect personality?
- How much does heredity influence personality?
- What features of your childhood influence your personality in adulthood?
- Why did personality differences evolve?
Whereas physically, we are very similar
- How does personality affect life outcomes (e.g. Health, happiness, career, law,
- What is “intelligence”, and does it matter in real life?
- Do you religious and political views depend on your personality?
- How does personality relate to sexuality?
- Two main approaches to the study of personality
o Idiographic approach: try to understand each individual’s complex,
What specifically makes you different from other people?
Used in biographies, fiction
It can help generate ideas to the way a person works
Ex: Bill Clinton had an abusive alcoholic step father, he
may have became president to gain love and affection
from many other people, that he didn’t receive from his
But... it’s inefficient
It would take too long to study many people this way in
order to see specific patterns
It doesn’t give a way to test ideas theories about
o Ex: Many people have problems with their
fathers, not many people go on to be the
Why is it this way for Bill Clinton but not
all others? If he had a good father, would he still be a
o Nomothetic approach: try to understand all people in terms of
By measuring lots of people, and see how personalities are
This way, you can test ideas about personality in
general, not just for one person
Looking at tendencies between types of people and
Looking to find what’s true “in general” among people
o Using lots of different characteristics- looking for
Basic Measurement Concepts
- To test ideas about personality, we need to measure personalities of many
people, then analyze and compare
- What types of properties do we want to measure with?
o We want these characteristics to show how big the differences are
between one another
E.g. The difference between 10 and 15 should mean the same
thing as the difference between 25 and 30
If our measurement give meaningful differences between
people, then we have “interval” scores
With interval scores, we can calculate means, standard
deviation, correlations, etc.
With personality differences, there will rarely be “true” or
“absolute” zero scores
Therefore, we can compare scores in terms of ratio
o It doesn’t make sense to say that one person is
“twice” as organized as this person
o When we measure psychological characteristics, we find that many
(but not all) of them have a continuous distribution (i.e., not
There are rarely distinctive types
People most have levels close to the average