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! http://www.buzzfeed.com/keelyflaherty/which-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! Nope!
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