Chapter 1: Thinking Critically with Psychological Science
- The Need for Psychological Science
- Underestimate perils of intuition
- Hindsight bias
a) Finding that something has happened makes it seem inevitable
b) Hindsight bias: the tendency to believe after learning an outcome, that one would have foreseen it. (Also known as the I-knew-it-all-along phenomenon.)
c) Errors in recollections and explanations show why we need psychological research
d) Just asking people how and why they felt/acted can be misleading-not because common sense is usually wrong, but b/c it more easily described what has happened than what will happen
e) It has been observed in various countries among both children and adults
f) Would be surprising if many of psych’s findings had not been foreseen b/c we all watch behavior
g) But sometimes intuition is wrong, research has overturned popular ideas, for ex. familiarity breeds contempt, dreams predict the future, and emotional reactions coincide with menstrual phase, and surprised us with discoveries
- Overconfidence
a) Once people know answer, hindsight bias makes it seem obvious and they become overconfident
b) Not much better at predicting social behavior: Robert Vallone and associates (1990) had students predict, on avg. students felt 84% confident in making self-predictions, later quizzes showed their predictions were only 71% correct
c) Even when students were 100% sure of themselves, self-predictions erred 15% of the time
d) Ohio State Uni. Psych Philip Tetlock (1998, 2005) collected > 27,000 expert predictions of world events
e) Repeated findings: predictions, which experts made with 80% confidence on avg. were right less than 40% of the time
f) Even those who erred maintained confidence by noting they were “almost right”
g) *hindsight bias and overconfidence often lead us to overestimate intuition, but scientific inquiry can help sift reality from illusion
- The Scientific Attitude
a) 1st curiosity-a passion to explore and understand without misleading or being mislead
b) Some questions are beyond science; to answer them requires leap of faith
c) With other ideas, proof is in pudding; does it work?
d) Scientific approach long history, even Moses, thru letting facts speak for themselves: empirical approach
e) 1700s, scientists scoffed at notion that meteorites had extraterrestrial origins; 2 Yale scientists dared to deviate from conventional opinion and were right
f) Today’s truths sometimes become tomorrow’s fallacies
g) Psychologists approach behavior with curious skepticism, asking 2 questions: What do you mean? How do you know?
h) When ideas compete, skeptical testing can reveal the ones that best match the facts
i) Also need humility: an awareness of our own vulnerability to error and an openness to surprises and new perspectives
j) If test subjects don’t behave as ideas predict, then so much the worse for ideas
k) 3 attitudes: curiosity, skepticism, and humility help make modern science possible
l) Founders had religious convictions which made them humble and skeptical of human authority
m) Today some religious nuts view science as threat, but scientific revolution was led mostly by religious people acting on the idea that to love God, one had to appreciate his work
n) We are all affected by preconceived ideas, but the ideal unifies psychologists with all scientists; scientists check and recheck others’ findings and conclusions
- Critical Thinking
a) It examines assumptions, discerns hidden values, evaluates evidence, and assesses conclusions
b) Critical thinking: thinking that does not blindly accept arguments and conclusions
c) Psychology’s critical inquiry has been open to surprising findings:
(1) Big loss of brain tissue early may have small long term effects
(2) Newborns recognize mom’s odor and voice
(3) Can learn with brain damage but unaware of learning
(4) Diverse groups have comparable levels of personal happiness
(5) Electroconvulsive shock therapy is good for severe depression
d) Also debunked popular presumptions:
(1) Sleepwalkers not acting out dreams
(2) Past experience not verbatim
(3) Most people don’t have weirdly low self-esteem and high self-esteem not all good
(4) Opposites don’t attract
e) Learned=/=believed
- How do Psychologists Ask and Answer Questions?
- Evaluating theories
- The Scientific Method
a) Theory: an explanation using an integrated set of principles that organizes observations and predicts behaviors or events
b) By linking facts and bridging them to deeper principles, theory offers useful summary
c) Hypothesis: a testable prediction, often implied by a theory
d) Letting us test and to reject/revise the theory, predictions give direction to research and specify what results would support/disconfirm the theory
e) Bias subjective observations, ever-present urge to see what we expect
f) To check biases, psychologists report research with operational definitions of procedures and concepts
g) Operational definition: a statement of the procedures (operations) use to define research variables; for ex. Human intelligence may be operationally defined s what an intelligence test measures
h) Operational definitions allow others to replicate original observations
i) Replication: repeating the essence of a research study, usually with different participants in different situations, to see whether basic finding extends to other participants and circumstances
j) If other researches recreate and get similar results, confidence in finding’s reliability grows
k) The scientific method: self-correcting process for asking questions and observing nature’s answers
l) Good theories explain by:
(1) Organizing and linking observed facts
(2) Implying hypotheses that offer testable predictions and, sometimes, practical applications
m) Research leads to revised theory that better organizes and predicts
n) Test hypotheses and refine theories using descriptive (which describe behaviors, often using case studies, surveys, or naturalistic observations), correlational (which associate different factors), and experimental (which manipulate factors to discover their effects) methods
- Description: psychologists observe and describe people more objectively and systematically
a) The Case Study
(1) Case study: an observation technique in which 1 person is studies in depth in the hope of revealing universal principles; for ex.: particular impairment after damage to certain brain region, children’s thinking, chimp capacity for understanding and language
(2) Case studies often suggest directions for further study and show what can happen, but can mislead if person studied is atypical
(3) *individual cases can suggest fruitful ideas; what’s true for all of us can be glimpsed in any one of us, but to discern the general truths that cover individual cases, we must use other research methods
b) The Survey
(1) Survey method looks at many cases in less depth
(2) Survey: a technique for ascertaining the self-reported attitudes or behaviors of a particular group, usually by questioning a representative, random sample of the group
(a) Wording effects
(i) Subtle changes in order of wording can have major effects
(ii) Critical thinkers reflect on how the phrasing of a question might affect people’s expressed opinions
(b) Random Sampling
(i) Accurate picture of whole population’s attitudes and experiences-representative sample
(ii) *the best basis for generalizing is from a representative sample of cases
(iii) Population: all the cases in a group being studied, from which samples may be drawn. (Note: except for national studies, this doesn’t refer to a country’s whole population.)
(iv) Random sample: a sample that fairly represents a population because each member has an equal chance of inclusion
(v) *before accepting survey findings, think critically: consider the sample; can’t compensate for unrepresentative sample by adding more people
c) Naturalistic Observation
(1) Naturalistic observation: observing and recording behavior in naturally occurring situations without trying to manipulate and control the situation
(2) Doesn’t explain, only describes
(3) Still reveals, ex. We thought only humans use tools, but chimps do too; paved way for later studies of animal behavior and further expanded out understanding
d) Whiten and Byrne (1988) saw baboon pretend to be attacked so mom drive others away from its good
e) More developed a primate species’ brain, more likely display deceptive behaviors (Byrne & Corp. 2004)
f) Human behavior
(1) Laugh 30x more often in social than alone, 17 muscles contort mouth and squeeze eyes, emit a series of 75-millisecond vowel-like sounds that are spaced about 1/5th of second apart (Provine 2001)
(2) Mehl and Pennebaker (2003) equipped 52 students from University of Texas with tape recorders; up to 4 days, recorder captured 30 seconds of students’ waking hours every 12.5 minutes, >10,000 half-minute slices (28% talking with someone, 9% computer keyboard)
(3) Levine and Norenzayan (1999) compare pace of life in 31 countries (operational definition pace of life included walking speed, speed postal clerks completed simple request and accuracy of public clocks) life fastest paced in Japan and Western Europe and slower paced in economically less-developed countries; colder climates live at faster pace (and more prone to die from heart disease)
g) Doesn’t control for all the factors that may influence behavior
h) Provide data for correlational research
- Correlation
a) Describing behaviors is 1st step toward predicting it, survey and naturalistic observation show us if one trait/behavior related to another
b) Correlation: a measure of the extent to which 2 factors vary together, and thus of how well either factor predicts the other
c) Statistical measures help figure how closely 2 things vary together and how well either 1 predicts the other
d) Correlation coefficient: a statistical index of the relationship between 2 things (from -1 to +1).
e) Scatterplots: a graphed cluster of dots, each of which represents the values of 2 variables, the slope of the points suggests the direction of the relationship between the two variables, the amount of scatter suggests the strength of the correlation (little scatter indicates high correlation)
f) Perfect correlations rarely occur
g) Each dot represents scattered values of 2 variables
h) Correlation (+) if 2 sets of scores tend to rise and fall together, saying correlation is “neg” says nothing of strength or weakness
i) (+1.00) perfect positive, no relationship (0.00), (-1.00) perfect negative
j) Correlation is neg if 2 sets relate inversely
k) Stats help see what naked eye misses, case by case, see no correlation
l) *correlation coefficient helps us see the world more clearly by revealing the extent to which 2 things relate
- *Correlation and Causation
a) Correlations help predict
b) No matter how strong the correlation, doesn’t prove cause-and-effect; 3rd factor could explain correlation
c) Association (not just correlation but also other associations verified by other non-experimental statistics) does not prove causation
d) *correlation indicates possibility of cause-effect relationship but does not prove causation
- Illusory Correlations
a) The perception of a relationship where none exists
b) When we believe there is a relationship, we are more likely to notice and recall instances that confirm our belief
c) *when we notice random coincidences, we may forget they are random and see them as correlated and deceive ourselves by seeing what is not there
- Perceiving Order in Random Events
a) Random sequences often don’t look random
b) Kahneman and Tversky (1972) found that most people believe HTTHTH most likely when all equally likely
c) Event with 1 out of a billion chance happens about 6 times a day
- Experimentation
- Experiment: a research method in which an investigator manipulates 1 or more factors (independent variables) to observe the effect on some behavior or mental process (the dependent variable); by random assignment of participants, the experimenter aims to control other relevant factors
- Correlational research can’t control for all possible factors
- Experiments enable that focus on the possible effects of 1 or more factors by:
a) Manipulating the factors of interest
b) Holding constant (“controlling”) other factors
- Random Assignment
a) No single experiment is conclusive
b) Random assignment: assigning participants to experimental and control groups by chance, thus minimizing pre-existing differences between those assigned to the different groups
c) Eliminates alternative explanations by holding constant all other factors
d) If behavior changes when we vary experimental factor, then factor is having an effect
e) *unlike correlational studies, which uncover naturally occurring relationships, an experiment manipulates a factor to determine its effect
f) 1 group receives treatment and other a placebo
g) Double-blind procedure: an experimental procedure in which both the research participants and research staff are ignorant (blind) about whether the research participants have received the treatment or a placebo, commonly used in drug-evaluation studies
h) Researches can check treatment’s actual effects apart from the participants’ belief in its healing powers and the staff’s enthusiasm for its potential
i) Placebo (Latin “I shall please”) effect: experimental results caused by expectations alone; any effect on behavior caused by the administration of an inert substance or condition, which the recipient assumes is an active agent
j) More expensive the placebo, the better if works
k) Must control for placebo effect
l) Double blind one way to create experimental and control group
m) Experimental group: in an experiment, the group that is exposed to the treatment, that is, to one version of the independent variable
n) Control group: the group that is not exposed to the treatment; contrasts with the experimental group and serves as a comparison for evaluating the effect of the treatment
o) By randomly assigning people to these conditions, fairly certain the 2 groups are otherwise identical; random assignment roughly equalizes the 2 groups in age, attitudes, and every other characteristic
p) With random assignment, conclude any later different between experimental and control groups will be result of treatment
- Independent and Dependent Variables
a) Independent variable: the experimental factor that is manipulated; the variable whose effect is being studied
b) Vary independently of other factors which random assignment control
c) Dependent variable: the outcome factor; the variable that may change in response to manipulations of the independent variable, usually behavior/mental process
d) Both variables given operational definition which specify procedures that manipulate the individual variable or measure the dependent variable
e) Distinction between random sampling (helps us generalize to a larger population) and random assignment (controls extraneous influences, which help infer cause and effect)