Chapter 1: Outline
Need for Psychological Science
* Hindsight bias and judgmental overconfidence show that we cannot rely on intuition and common sense. Critical thinking must also be employed in order to perceive facts from nonsense.
Hind sight Bias
* The thought that once a person find out the outcome, that the person knew the outcome all along and could have predicted it.
* Proves that we need psychological research
* Common sense describes what has happened more easily than predict what will happen
* Thinking is limited
* Even when you are 100% sure about something, self prediction may change up to 15% of the time.
* When prediction becomes wrong, individual’s attempt the ‘I was close’ excuse
* Often leads to the overestimation of our potential.
* Skepticism and humility must be added to come back to reality
* Sometimes refutes skeptics
* Being skeptical but not cynical, open but not gullible
* Skeptical testing could separate the real facts
* Requires skepticism and humility
* Need to reject our own ideas
* Copernicus and Newton, are examples of people who used the scientific attitude
* Critical Thinking examines assumptions, discerns hidden values, evaluates evidence and assess’s conclusion without blindly accepting arguments and conclusions.
* Scientific Theory explains through principles that organizes and predicts behaviors or events.
* By organizing isolated facts, theory simplifies things.
* Connection of observed dots, we may discover a pattern
* Hypothesis is testable prediction, often started by a theory
* Research allows one to test or reject the theory
* Operational Definition is a statement of the procedures used to define research variables.
* Replication when a procedure could be repeated with different participants in different situations to see whether the same result is found.
* A theory is successful if it links and organizes observed facts and if it implies hypothesis that offer testable predictions and practical applications.
* An observation technique in which one person is studied in depth in hope of revealing universal principles
* Case studies can suggest hypotheses for further study.
* Unrepresentative information can lead to mistaken judgments and false conclusions.
* Anecdotal stories may elevate the truth
* Does not work to find the general truths that cover individual cases
* Looks at many cases in less depth
* Asks individuals about their behaviors and opinions
* Answers depend on wording
* May use random sampling
* False consensus effect is the tendency to overestimate the extent to which others share our beliefs and behaviors
* Populations includes all the cases in a group from which samples may be drawn from a study
* Random sampling represents a populations because each member has an equal chance of inclusion
* Very large samples may be more reliable
* Basis of generalizing is from representative sample of cases
* Observing and recording behavior in naturally occurring situations without trying to manipulate and control the situation
* Does not explain behavior, it describes it
* Robert Levine and Ara Norenzayan – compared pace of life
* Can be used with correlation research
* When two traits seem to accompany each other, they correlate
* Correlation coefficient is a statistical measure of a relationship
* Reveals how closely two things vary together and thus how well wither one predicts the other
* Scatter plots show how closely related the traits are associated with
* Each point plots the value of the two variables
* Positive correlation means that two variables seem to rise or fall together
* A negative correlation could mean inverse as well as negative relationships
* Inverse means that while one variable is increasing, the other is decreasing
* A weak correlation means that there is little or no relationship- the coefficient is then zero
* Correlation indicates the possibility of a cause-effect relationship but does not prove the cause.
* A perceived non existent relationship
* Explains superstitions, beliefs.
* More likely to notice and remember the occurrence of two events in sequence
* Can be easily deceived by estimating that there is a correlation amidst random events.
Perceiving order in random events
* Random sequences often don’t look random
* Example- Flipping coins – 50% of getting each side
* Streaks may be found in any random data
* Patterns or sequences occur naturally in random data
Exploring Cause and Effect
* Experiment is a research method in which an investigator manipulates one or more factors to observe the effect on some behavior or mental process. By random assignment of participants, the experimenter aims to control other relevant factors.
* Independent Variable is being manipulated
* Dependent Variable is the effect being observed.
* Double blind procedures- when an experiment is being performed without the knowledge of either the participant nor the administer
* Placebo Effect is researching the effect of expectations, could be used to see whether a medicine is needed or not
* Experimental Condition is the condition of an experiment that exposes participants to the treatment.
* Control condition is the condition of an experiment that contrasts with the experimental condition and serves as a comparison for evaluating the effect of the treatment
* Random assignment is assigning participants to by chance, minimizes existing differences.
Independent and Dependent Variables
* The Independent Variable is the value being manipulated within a given experiment
* The dependent variable is the effect produced by manipulating the independent variable.
* A variable is anything that can vary
* Random assignment is preferred so that all other variables could be equal and not favor one thing.
* By throwing out a big round number, one could easily mistake reality. Like when we compare percentages and what they actually mean. An example given in the textbook is- “10% of people are lesbians or gay men. Or is it 2 to 3% as suggested by various surveys?”
* One important thing while reading graphs is not to forget to read scale and figure out the range. The same graph could look different if given different scales or a different range.
Measures of Central Tendency
* A single score that represents a whole set of scores is also known as the measure of central tendency.
* Mode is the most frequent number repeated within a given set of numbers
* Median is the midpoint
* Mean is the average of the numbers. You can find this out by adding up all the given numbers and then dividing it by the number of numbers you have. The mean could be exaggerated or diluted based on a few extreme scores. Like for example, the mean of 3, 4, 6 and 201 is 53.5, even though there are not many numbers above 53.5. since the information is skewed.
Measures of Variation
* Variation describes how similar or different scores could be. When a person has low variability, we may predict his next move, since there is not much of a chance that he will change his next move.
* The range is determined based on how far the lowest and highest scores are.
* The standard of deviation is a measure of how much numbers may deviate from one another. It shows how much individual numbers vary from the mean. It is more informative than just the mean.
When is an observed difference reliable?
* Three principles that shall make an observed difference more reliable includes
1. Representative samples are better than biased samples
2. Less-variable observations are more reliable that those that are more variable. (consistent scores are more reliable than those with more variation.)
3. When a study includes more cases, it is more reliable than having a study with fewer cases.
When is a difference significant?
* When there is a big difference among an average, that difference is known as the statistical significance. It also means that this difference was not due to chance variations and that the mean is reliable.
* Statistical difference also shows the ‘likelihood’ that the result will happen by chance.
Can Libratory Experiments illuminate Everyday Life?
* The main idea is that ‘the resulting principles-not the specific findings will help everyday behaviors.’
* Douglas Mook claims that the experiment’s purpose is not re-create the exact behaviors of everyday life but to test theoretical principles.
Does Behavior Depend on One’s Culture
* Culture is the shared ides and behaviors that one generation passes on to the next.
* It does matter since it influences our perspective on certain topics.
* Heritance does play a role though, since dyslexia can be seen more in certain races than others, the variation of languages are influenced by our cultures and society and so does the way we live our lives, the choices that we make.
Does Behavior vary by gender?
* Gender does play a role in behavior.
* Women are more likely to build relationships and carry on a conversation and men are more likely to relate through advice. This information shows us a way to communicate differently with each gender. It is a known fact that men are less likely to talk about personal feeling as much as woman, such differences, require different approaches.
Why do Psychologists study animals?
* Human physiology resembles that of many other animals.
* Animal experiments could lead to cures/vaccines for humans
Is it ethical to experiment on animals?
* Researchers defend themselves by stating that the number of animals they use for research is only 1% of the number of animals killed for food.
* Psychologists for the Ethical Treatment of animals want researchers to use naturalistic observation while testing rather than libratory manipulation.
* Ethics vary from culture to culture
* Some say that the benefits out way the costs
* Scott Plous noted that each individual has a list of animals they are more concerned about.
* APA advocates minimal pain and stress placed upon animals.
Experimenting on people
* The APA states that in order to experiment on people, the following guidelines must be followed:
1. Obtain the informed consent of potential participants
2. protect them from harm and discomfort
3. treat information about individual participants confidentially
4. fully explain the research after the experiment
Value of Judgments
* Bias definitely plays a role in how an individual may interpret results and study it.
* Plays a role in which goals we would like to reach
* ‘power to deceive as well as enlighten’
* Addresses common problems, meant to enlighten.
The Scientific Attitude
* Scientific approach that is skeptical and open-minded
* To shift away from illusions to reality, one must use Smart thinking or critical thinking: thinking that does not blindly accept things, but approaches with skepticism and examines the evidence carefully; Ask how did they know, on guts and instinct? Are the evidence biased?
* However, must remember to have humility as too extreme would be stubbornness
The Limits of Intuition and Common Sense
* Intuition often ends up nowhere
* Tend to use a lot hindsight bias: tendency to believe that one would have known it after the results are shown;
* Seems like common sense; The answer was right there and look how obvious it was
* Experience it usually when looking back on history; eg. Glen Clark and the fast ferries
* Humans tend to be overconfident, think we know more than we actually do (probably result of self-serving bias)
* Hindsight causes us to be overconfident as we believe we would have picked the answer when the results are in front of us
The Scientific Method
* Scientific theory: explanation using set of principles to organise/predict observations
* No matter how good theory sounds, must put it to test
* Must imply testable prediction = hypothesis
* Beware of bias when testing
* Good experiment can be replicated: the experiment can be repeated and would yield constant results; done with a different group of people or by a different person ending with constant results
* Theory useful if:
1. effectively organises range of observations
2. implies clear predictions
* Case study: research method where one person is studied in depth to find universal principles (things that apply to all)
* Drawback is that the individual being studied could be atypical, results not universally contained
* Survey: research method to get the self-reported attitudes/behaviours of people
* Looks at cases less depth and wording of question affects the response given (framing)Tend to hang around group similar to us so using them as study is wrong
* False consensus effect: tendency to overestimate other’s agreement with us; eg. Vegetarians believe larger amount of pop. is vegetarian than meat-eaters
* Population: all the cases in the group being studied
* To make a good sample, use random sampling: sample that gives each case a good chance of being studied to ensure results within range
* Naturalistic observation: observing and recording behaviour in natural settings with any control on situation
* Like case study & survey, doesn’t explain behaviour
* When finding a trait that accompanies another, not resulting effect, but correlation: the way 2 factors vary together and how well one predicts the other
* Positive correlation: direct relationship where factors increase or decrease together
* Negative correlation: inverse relationship where one factor goes up while one goes down
* Does not explain cause, simply show relationship between factors
* Illusory correlation: perceiving correlation when none exist; Notice random coincidences as not random, rather as correlated
* To isolate cause & effect, conduct experiments
* Experimental condition: condition that exposes subjects to treatment
* Control condition: condition that serves as a comparison to see effects of treatment on experimental condition subjects
* Use random assignment: assigning subjects to experimental/control groups randomly to ensure no bias
* Independent variable: experimental factor being manipulated and studied (by itself, alone, no need to depend on something) * x-axis
* Dependent variable: experimental factor that depends on independent variable and changes in response to it * y- axis
* Placebo: an inert substance/condition that maybe administered instead of a presumed active agent
* Double-blind procedure: procedure in which the experimenter and the subject noth don’t know which treatment is given
* 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)
* Critical Thinking: thinking that does not blindly accept arguments and conclusions; rather, it examines assumptions, discerns hidden values, evaluates evidence, and assesses conclusions
* Theory: an explanation using an integrated set of principles that organizes observations and predicts behaviors or events
* Hypothesis: a testable prediction, often implied by a theory
* Operational Definition: a statement of the procedures (operations) used to define research variables; for example, human intelligence may be operationally defined as what an intelligence test measures
* Replication: repeating the essence of a research study, usually with different participants in different situations, to see whether the basic finding extends to other participants and circumstances
* Case Study: an observation technique in which one person is studied in depth in the hoe of revealing universal principles
* Survey: a technique for ascertaining the self-reported attitudes or behavior of a particular group, usually by questioning a representative, random sample of the group
* Population: all the cases in a group being studied, from which samples may be drawn (note: except for national studies, this does not refer to a country’s whole population)
* Random Sample: a sample that fairly represents a population because each member has an equal chance of inclusion
* Naturalistic Observation: observing and recording behavior in naturally occurring situations without trying to control or manipulate the situation
* Correlation: a measure of the extent to which two factors vary together, and thus of ow well either factor predicts the other
* Correlation Coefficient: a statistical index of the relationship between two things (from -1 to +1)
* Scatterplot: a graphed cluster of dots, each of which represents the values of two variables; the slop of the points suggests the direction of the relationship between the two variables; the amount of scatter suggests the strength of the correlations (little scatter = high correlation)
* Illusory Correlations: the perception of a relationship where none exists
* Experiment: a research method in which an investigator manipulates on 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
* Random Assignment: assigning participants to experimental and control groups by chance, thus minimizing preexisting differences between those assigned to the different groups
* Double-blind Procedure: an experimental method where neither the participants nor the research staff know whether one person got the treatment or the placebo
* Placebo Effect: experimental results caused by expectation alone; any effect on behavior cased by the administration of an inert substance or condition, which the recipient assumes is an active agent
* Experimental Group: the group exposed to the treatment (to one version of the independent variable)
* Control Group: the group that does not receive the treatment; serves as a comparison for evaluating the effect of the treatment
* Independent Variable: the variable being manipulated and whose effect is being studied
* Confounding Variable: a factor other than the independent variable that might produce an effect in an experiment
* Dependent Variable: the outcome factor; the variable that may change in response to manipulations of the independent variable; the variable being measured
* Mode: most frequently occurring score(s) in a distribution
* Mean: the average (add scores and divide by the number of scores that there are)
* Median: the middle score in a distribution; half the scores are above it and half are below it
* Range: the difference between the highest and lowest scores in a distribution
* Standard Deviation: a computed measure of how much scores vary around the mean score
* Normal Curve (normal distribution): a symmetrical, bell-shaped curve that describes the distribution of many types of data; most scores fall near the mean (68% fall within one standard deviation of it, 95% fall within two, and 98% fall within three)
* Statistical Significance: a statistical statement of how likely it is that an obtained result occurred by chance
* Culture: the enduring behaviors, ideas, attitudes, and traditions shared by a group of people and transmitted from one generation to the next
* Informed Consent: an ethical principle that research participants be told enough to enable them to choose whether they wish to participate in an experiment
* Debriefing: the post-experimental explanation of a study, including its purpose and any deceptions, to its participants