Why Are People Different? Intro to Psych 4/8/14

Human Universals  What have we discussed so far?  Human Universals: what everybody shares  Language, emotions, development, rationality  Interesting stuff, but maybe not what we’re interested in????

Human Differences  Today we’ll discuss:  Why we are different – theories about what makes us different in a psych way  Where do those differences come from?  How are people different?  Sexual Identity: gender  Sexual Orientation: who you are attracted to  Happiness: how happy are you?

Differences  2 Main Factors at the root of all human differences:  Personality  Intelligence  How do we explain them, how do we characterize them, and why do they exist in the first place?

Differences: Personality  A person’s style in dealing with the world and with other people  A stable trait across situations and time (something you carry around with you)  Words we use to describe someone’s personality:  Impulsive, irresponsible, lazy, good-hearted, reliable, kind, angry, etc

Differences: Personality  How do we scientifically describe personality differences?  Tests!  Tests must be/have:  Reliable: no error in measurement, can be trusted over time  Validity: the measures what it’s supposed to measure It’s important to remember something can be reliable but not valid and something can be valid but not reliable

Differences: Personality  Personality Tests  There are a gazillion, especially on the Internet  Let’s take one! h-peanuts-character-are-you

Differences: Personality  Real Personality Tests  Rorschach Inkblot Test  Originally used only for psychiatric cases, but now very common  About 80% of clinical psychologists claim to use it  Catholic seminaries use it for people who want to join the seminary  Idea is that saying what you see in the inkblots gives great insight into nature of their personality, into what they are

Differences: Personality  Created by a man named Hermann Rorschach  Devoted his entire life to the inkblot test  His nickname as a teenager was “Inkblot”

Rorschach Inkblot Test

 Turns out there are right and wrong answers to the test  Also turns out the test is totally useless  But people love it and it gets used all over the place  That’s why the images are on the Internet, for everyone to use  But they’re totally worthless as psychological measures of personality

Differences: Personality  “The Big Five”  Five main personality factors that make us different  “Neurotic vs Stable”  nutty & worrying or stable?  Extrovert vs Introvert  Open to experience or closed to experience?  Agreeable vs Non-agreeable  friendly vs rude, selfish  Conscientious vs Not Conscientious  Careful & reliable vs careless & undependable

Differences: Personality  O – openness  C – conscientiousness  E – extroversion  A – agreeableness  N – neuroticism

Differences: Personality  Is the theory of “The Big Five” believable?  Actually, yes!  There is reliability  If people are tested over the years, the results don’t change much  Once you pass age 30, your personality traits become very stable & don’t change much  There is validity  Different people agree on these traits to characterize a person  You leave a personality trail!

Differences: Personality  Good predictors of real-world behavior  Conscientiousness  Relates to how faithful you are to your spouse  Openness  Relates to how likely you are to change your job  Extroverted  Relates to how often you look people in the eye and to how many sexual partners you will have

Differences: Intelligence  No easy definition of intelligence  Abstract reasoning, problem solving, capacity to acquire knowledge, memory, creativity, math, language, etc  It’s one of those things you just have a gut feeling about  You know it when you see it/experience it Guess who the smart one is!

Differences: Intelligence Nope! Heck no! Intelligent!

Differences: Intelligence  But we can’t just go around calling people “smart” and “dumb”  We need to be able to describe what is “smart” and what is “dumb”  We need to be able to define and measure what is intelligence

Differences: Intelligence  Charles Spearman  Two factors to intelligence  “G” = general intelligence  “S” = specific ability  Score on any given test depends on a combination of these two factors  “G” accounts for the similarity in test results  “S” accounts for the differences in test results

Differences: Intelligence  Sports will help us understand!  You’re in Gym Class and there are a bunch of different athletic tests  Running test, basketball shooting test, swimming test, fencing test, wrestling test, etc (Ten tests total)  We discover the scores on each test are NOT independent of each other

Differences: Intelligence  People who are good at one athletic thing tend to be good at another  The same is true for “G” and “S”  “S” – how good you did on each athletic test  “G” – how good you did overall

Differences: Intelligence  Modern Intelligence Tests  The Wechsler tests  For children and adults  Scoring:  Average is 100  68% get between 85 – 115  95% get between 70 – 130  0.13% have an IQ above 145

Differences: Intelligence  How valid are IQ tests?  IQ is strongly related to many important educational occupational, economic, & social outcomes  IQ matters for:  Social achievement  Prestigious job positions  On the job performance  Other work-related variables

Differences: Intelligence  Lots of controversy about why this connection between IQ & success exists  Is the effectiveness of an IQ test in determining someone’s abilities a self- fulfilling prophecy?  If your IQ determines your success in life, are you doing things to find success to validate your IQ, or is your IQ bringing about this success?

Differences: Intelligence  Example:  Your IQ is related to your success in getting into a good school like Harvard  But the reason for this is because they give you an IQ test to get in – the SATs  To get into graduate school, you have to take the GRE, another IQ test  So is it your IQ getting you in, or is the score you get that allows you in?

Differences: Intelligence  A society that puts a lot of weight on IQ tests as a determiner of success will eventually begin to put that importance on the IQ itself

Behavioral Genetics  2 reasons we are who we are:  Your genes  Your environment  Shared environment: differences caused by phenomena people raised in the same household share  Ex: I’m neurotic because I have lousy parents  Non-shared environment: everything else  Ex: I’m neurotic because I won the lottery at 21 and all that money messed me up

Behavioral Genetics  How do we figure out which psychological differences are genetic and which are environmental?  We need to remember the clever things about genetics and environment like…  Some people are clones  Identical twins!  They share 100% of the same genetic material

Behavioral Genetics  Fraternal twins  Just like regular siblings  Share 50/50 genetic material  Adopted siblings  Zero shared genes

Behavioral Genetics  What do all of these people have in common?  Some of them may not be genetically the same, but remember, they are all the same in ENVIRONMENT  They were all raised in the same house by the same parents

Behavioral Genetics  Studying families with identical, fraternal, or adopted siblings can help psychologists learn more about what makes us different: environment or genetics  Are identical twins much more similar than fraternal twins?  If so, big role of genes -- high heritability  Are identical twins just as similar as fraternal twins?  If so, low role of genes -- low heritability

Behavioral Genetics  Are adopted children highly similar to their brothers and sisters?  If so, high role of shared environment  What about identical twins raised apart?  Genetically identical  Environmentally different

Behavioral Genetics  Studies have shown identical twins raised apart are often VERY alike  Similar views on death penalty, religion, music, etc  Similar rates of behavior in crime, gambling, divorce  Some even have weird similarities: getting in trouble for fake sneezing in elevators, bursting into giggles at every moment  These things can’t be environmental, they weren’t raised together!

Behavioral Genetics  2 findings of behavioral genetics:  There is high heritability for almost everything  Intelligence, personality, how happy you are, how religious you are, your political orientation, your sexual orientation  IQ can be very different without any genetic differences at all  The Flynn Effect

Behavioral Genetics  The Flynn Effect  A finding that says people have been getting smarter  You are much smarter, on average, than your parents  IQ tests hide this  Why???  Because the average is always 100 on the test

Behavioral Genetics  Example:  “Dad, I got 120 on my IQ test!”  “Great son, I got 122 when I was your age”  But this doesn’t acknowledge that the son’s test was WAY harder than the Dad’s  As people get better at the test, it has changed over the years to get harder and harder

Behavioral Genetics  Almost everything that isn’t genetic is due to non-shared environments  Shared environment counts for little (or nothing)  When it comes to personality or intelligence, an adopted child is no more similar to his siblings than he is to a stranger

Behavioral Genetics  So then, do parents even matter?  If non-shared environment is responsible for so much, what role then do parents play in shaping us?  For starters, they played a huge role in actually SHAPING us physically – with their genes  But once we were conceived, they stopped having an effect on us

Behavioral Genetics  But wait? Of course parents have an effect on their children  Good kids have good parents  Religious kids have religious parents  Bookish kids have bookish parents  Poor kids have poor parents  Brilliant kids have brilliant parents  These connections can be explained in different ways…

Behavioral Genetics  People think parents do something that affects their kids  They do, they give their genes  But another possibility is the child affecting the parents  Maybe a bookish kid is more likely to get their parents to read to them  Maybe a troublemaker kid is more likely to cause their parents to hit them

Things that make you go HMMMMM…..