How is psychology How is psychology different from different from philosophy?philosophy?

What qualifies What qualifies research as science?research as science?

Psychological research must meet Psychological research must meet certain criteria in order to be certain criteria in order to be considered scientific.considered scientific.

Research must be: Research must be: 1. Replicable1. Replicable 2. Falsifiable2. Falsifiable 3. Precise 3. Precise 4. Parsimonious4. Parsimonious

ReplicableReplicable

Research is replicable when others can Research is replicable when others can repeat it and get the same results. repeat it and get the same results.

Q: If something is only true once, should Q: If something is only true once, should we trust it?we trust it?

FalsifiableFalsifiable

A good theory or hypothesis also must be A good theory or hypothesis also must be falsifiablefalsifiable, which means that it must be , which means that it must be stated in a way that makes it possible to stated in a way that makes it possible to reject it. In other words, we have to be able reject it. In other words, we have to be able to prove a theory or hypothesis wrong.to prove a theory or hypothesis wrong.

FalsifiableFalsifiable

Example: Example:

Some people theorize that the Loch Ness Monster not Some people theorize that the Loch Ness Monster not only exists but has become intelligent enough to only exists but has become intelligent enough to elude detection by hiding in undiscovered, elude detection by hiding in undiscovered, undetectable, underwater caves. This theory is not undetectable, underwater caves. This theory is not falsifiable. Researchers can never find these falsifiable. Researchers can never find these undiscovered caves or the monster that supposedly undiscovered caves or the monster that supposedly hides in them, and they have no way to prove this hides in them, and they have no way to prove this theory wrong.theory wrong.

PrecisePrecise

To make hypotheses more precise, psychologists use To make hypotheses more precise, psychologists use operational definitions to define the variables they study. operational definitions to define the variables they study. Operational definitionsOperational definitions state exactly how a variable will state exactly how a variable will be measured.be measured.

Ex.: Ex.: A psychologist conducts an experiment to find out whether A psychologist conducts an experiment to find out whether

toddlers are happier in warm weather or cool weather. She toddlers are happier in warm weather or cool weather. She needs to have an operational definition of happiness so that needs to have an operational definition of happiness so that she can measure precisely how happy the toddlers are. She she can measure precisely how happy the toddlers are. She might operationally define happiness as “the number of might operationally define happiness as “the number of smiles per hour.smiles per hour.

ParsimoniousParsimonious

The principle of parsimony maintains that researchers should The principle of parsimony maintains that researchers should apply the simplest explanation possible to any set of apply the simplest explanation possible to any set of observations. observations.

Example: Example: Suppose a student consistently falls asleep in her statistics class. Suppose a student consistently falls asleep in her statistics class.

She theorizes that before each class, her statistics professor She theorizes that before each class, her statistics professor secretly sprays her seat with a nerve gas that makes her very secretly sprays her seat with a nerve gas that makes her very drowsy. If she had applied the principle of parsimony, she drowsy. If she had applied the principle of parsimony, she would not have come up with this theory. She can account would not have come up with this theory. She can account for her sleepiness with a much simpler and more likely for her sleepiness with a much simpler and more likely explanation: she finds statistics boring.explanation: she finds statistics boring.

The ExperimentThe Experiment

An experiment involves a set of An experiment involves a set of controlled conditions that aim to controlled conditions that aim to confirm a hypothesis.confirm a hypothesis.

Hypothesis Hypothesis refers to a statement of refers to a statement of cause and effect:cause and effect:

““Higher environmental temperatures lead Higher environmental temperatures lead to more aggression.”to more aggression.”

Experimental VariablesExperimental Variables

To test a hypothesis, an experimenter To test a hypothesis, an experimenter defines the variables of the hypothesis:defines the variables of the hypothesis: Cause: Cause: Independent variableIndependent variable (IV) (IV)

temperature: can be manipulated with intenttemperature: can be manipulated with intent Effect: Effect: Dependent variableDependent variable (DV) (DV)

aggressionaggression: # of acts of verbal/aggression in an hour: # of acts of verbal/aggression in an hour

The experimenter “manipulates” the IV and The experimenter “manipulates” the IV and measures the DV to test the hypothesis.measures the DV to test the hypothesis.

Experimental IssuesExperimental Issues

ControlsControls are important for determining causality are important for determining causality the the onlyonly difference between the experimental difference between the experimental

and control groups is the presence or absence of and control groups is the presence or absence of the IV.the IV.

Placebo effectsPlacebo effects represent changes in behavior that are represent changes in behavior that are related to expectations of a treatment.related to expectations of a treatment. placebo effects are controlled by a “blind” placebo effects are controlled by a “blind”

control group control group Experimenter bias Experimenter bias refers to expectations that refers to expectations that

influence a participant’s behavior.influence a participant’s behavior. example: Clever Hans, the horse who could do example: Clever Hans, the horse who could do

mathmath can be controlled using double blind procedurescan be controlled using double blind procedures

Non-Experimental Non-Experimental ResearchResearch

Naturalistic observationNaturalistic observation refers to systematic recording refers to systematic recording of behavior in a natural state or habitat.of behavior in a natural state or habitat. e.g. observing apes in the wilde.g. observing apes in the wild

Surveys Surveys are instruments designed to sample attitudes or are instruments designed to sample attitudes or behaviors. behaviors. e.g., asking students at a rally how they feel about e.g., asking students at a rally how they feel about

animal rights issuesanimal rights issues

A A case studycase study is an in-depth study of a single person. is an in-depth study of a single person. e.g., Freud used the case study method to study e.g., Freud used the case study method to study

anxietyanxiety

CorrelationsCorrelations refer to looking at the relationship refer to looking at the relationship between two variables without manipulating them.between two variables without manipulating them.

Correlation Correlation TechniquesTechniques

The correlation technique assesses the degree of The correlation technique assesses the degree of association between 2 variables. association between 2 variables.

Correlations vary in direction:Correlations vary in direction: PositivePositive association: increases in the value of association: increases in the value of

variable 1 are associated with increases in variable 1 are associated with increases in variable 2 (e.g., smoking and risk of cancer)variable 2 (e.g., smoking and risk of cancer)

NegativeNegative association: increases in variable 1 association: increases in variable 1 are associated with decreases in the variable 2 are associated with decreases in the variable 2 (e.g., years of education and risk of Alzheimer’s (e.g., years of education and risk of Alzheimer’s disease)disease)

No relation: values of variable 1 are not related No relation: values of variable 1 are not related to variable 2 (e.g., years of education and to variable 2 (e.g., years of education and height)height)

Correlations also vary in strength of the relationshipCorrelations also vary in strength of the relationship-1 to 1-1 to 1

Interpreting Interpreting CorrelationsCorrelations

Fig. 1.5

Correlation Take Home Correlation Take Home Line:Line:

Correlation does NOT imply causation!

What are the Goals of What are the Goals of Psychology as a Science?Psychology as a Science?

Attempts to:Attempts to:

1.1. Describe behaviorDescribe behavior

2.2. Explain behaviorExplain behavior

3.3. Predict behaviorPredict behavior

4.4. Control behaviorControl behavior Uses scientific method, not Uses scientific method, not

common sense. common sense.

ScienceScience vs. vs. Common Common SenseSense

Objective data collection

Reliance on evidence

Systematic observation

Subjective data collection

Ignores counterevidence

Hit or miss observation

Science versus Pseudo-Science versus Pseudo-ScienceScience

SystematicSystematic TestableTestable ReliableReliable UnbiasedUnbiased Self-CorrectingSelf-Correcting

Extending EvidenceExtending Evidence

Specific truths are Specific truths are deduceddeduced from from general truthsgeneral truths

General truths are General truths are inducedinduced from from specific truthsspecific truths

Science & ProofScience & Proof

A A deductiondeduction is proven if the general is proven if the general premise is true and the logic is valid.premise is true and the logic is valid.

An An inductioninduction goes beyond the known goes beyond the known data, and thus can never be proven.data, and thus can never be proven.

Science does not prove things, because all information about the outside observable world is inductive.

ScienceScience

Terminology:Terminology: Hypothesis - a possible way things could Hypothesis - a possible way things could

bebe Theory - an explanation for the way Theory - an explanation for the way

things are, usually supported by a lot of things are, usually supported by a lot of data.data.

Advantages of science:Advantages of science: Scientific methods are deductiveScientific methods are deductive Science is more systematic, and less subject Science is more systematic, and less subject

to human biasto human bias

Judging TheoriesJudging Theories

Fit to the dataFit to the data Quality of the dataQuality of the data Ability to predictAbility to predict Ability to explainAbility to explain Ability to controlAbility to control

Pseudo-sciencePseudo-science

Why people believe:Why people believe: People like excitement People like excitement People are prone to wishful thinkingPeople are prone to wishful thinking People are naïve and trustingPeople are naïve and trusting People remember hits, ignore missesPeople remember hits, ignore misses

Psychological ResearchPsychological Research Two forms of psychological Two forms of psychological

research:research: Basic researchBasic research seeks answers for the seeks answers for the

purpose of increasing knowledge.purpose of increasing knowledge. e.g. What role do the frontal lobes play e.g. What role do the frontal lobes play

in memory?in memory? Applied researchApplied research seeks answers for seeks answers for

specific problems.specific problems. e.g. What types of memory strategies e.g. What types of memory strategies

and rehabilitation strategies are most and rehabilitation strategies are most effective for people with frontal lobe effective for people with frontal lobe injuries?injuries?

Basic Cognitive Psychology Research

Baldo et al. (1998)

LEFT

Basic Cognitive Psychology Research

Baldo et al. (1998)

Applied Applied Cognitive Cognitive PsychologPsycholog

yy

The Scientific MethodThe Scientific Method

The ExperimentThe Experiment

An experiment involves a set of An experiment involves a set of controlled conditions that aim to controlled conditions that aim to confirm a hypothesis.confirm a hypothesis.

Hypothesis Hypothesis refers to a statement refers to a statement of cause and effect:of cause and effect:

““Higher environmental temperatures Higher environmental temperatures lead to more aggression.”lead to more aggression.”

““Exposure to marijuana increases Exposure to marijuana increases appetite.”appetite.”

Experimental VariablesExperimental Variables

To test a hypothesis, an experimenter To test a hypothesis, an experimenter defines the variables of the defines the variables of the hypothesis:hypothesis: Cause: Cause: Independent variableIndependent variable (IV) (IV)

marijuanamarijuana: plain cigarette versus cigarette : plain cigarette versus cigarette containing 5 mg of THC (the active ingredient containing 5 mg of THC (the active ingredient in marijuana)in marijuana)

Effect: Effect: Dependent variableDependent variable (DV) (DV) appetiteappetite: grams of ice cream consumed in 1 : grams of ice cream consumed in 1

hourhour

The experimenter “manipulates” the The experimenter “manipulates” the IV and measures the DV to test the IV and measures the DV to test the hypothesis.hypothesis.

Experimental IssuesExperimental Issues ControlsControls are important for determining causality are important for determining causality

the the onlyonly difference between the experimental difference between the experimental and control groups is the presence or absence and control groups is the presence or absence of the IV.of the IV.

Placebo effectsPlacebo effects represent changes in behavior represent changes in behavior that are related to expectations of a treatment.that are related to expectations of a treatment. placebo effects are controlled by a “blind” placebo effects are controlled by a “blind”

control group control group Experimenter bias Experimenter bias refers to expectations that refers to expectations that

influence a participant’s behavior.influence a participant’s behavior. example: Clever Hans, the horse who could do example: Clever Hans, the horse who could do

mathmath can be controlled using double blind can be controlled using double blind

proceduresprocedures

Non-Experimental Non-Experimental ResearchResearch

Naturalistic observationNaturalistic observation refers to systematic refers to systematic recording of behavior in a natural state or recording of behavior in a natural state or habitat.habitat. e.g. observing apes in the wilde.g. observing apes in the wild

Surveys Surveys are instruments designed to sample are instruments designed to sample attitudes or behaviors. attitudes or behaviors. e.g., asking students at a rally how they feel e.g., asking students at a rally how they feel

about animal rights issuesabout animal rights issues A A case studycase study is an in-depth study of a single is an in-depth study of a single

person.person. e.g., Freud used the case study method to e.g., Freud used the case study method to

study anxietystudy anxiety CorrelationsCorrelations refer to looking at the relationship refer to looking at the relationship

between two variables without manipulating between two variables without manipulating them.them.

Correlation TechniquesCorrelation Techniques The correlation technique assesses the The correlation technique assesses the

degree of association between 2 variables. degree of association between 2 variables. Correlations vary in direction:Correlations vary in direction:

PositivePositive association: increases in the value of association: increases in the value of variable 1 are associated with increases in variable 1 are associated with increases in variable 2 (e.g., smoking and risk of cancer)variable 2 (e.g., smoking and risk of cancer)

NegativeNegative association: increases in variable 1 association: increases in variable 1 are associated with decreases in the variable 2 are associated with decreases in the variable 2 (e.g., years of education and risk of (e.g., years of education and risk of Alzheimer’s disease)Alzheimer’s disease)

No relation: values of variable 1 are not No relation: values of variable 1 are not related to variable 2 (e.g., years of education related to variable 2 (e.g., years of education and height)and height)

Correlations also vary in strength of the Correlations also vary in strength of the relationship. (-1 to 1)relationship. (-1 to 1)

Interpreting Interpreting CorrelationsCorrelations

Fig. 1.5

Correlation Take Home Correlation Take Home Line:Line:

Correlation does NOT imply causation!

Stanley Milgram’s Stanley Milgram’s Obedience StudyObedience Study

1963 social psychology experiment, 1963 social psychology experiment, subjects thought they were shocking subjects thought they were shocking another person to promote “learning”another person to promote “learning”

Many subjects delivered high level Many subjects delivered high level shocks and were upset when they later shocks and were upset when they later learned the true nature of the learned the true nature of the experimentexperiment

This study, This study, and other factorsand other factors, led to , led to much more stringent APA research much more stringent APA research guidelines guidelines

What are APA Ethical What are APA Ethical Guidelines for human Guidelines for human

participants?participants? informed consentinformed consent awareness of risksawareness of risks confidentialityconfidentiality deception can be used ONLY if deception can be used ONLY if

benefits justify it and there is no benefits justify it and there is no other way to do the studyother way to do the study

What are APA Ethical What are APA Ethical Guidelines Guidelines

for animal for animal subjectssubjects?? Researchers must ensure Researchers must ensure

“appropriate consideration of [the “appropriate consideration of [the animal’s] comfort, health, and animal’s] comfort, health, and humane treatment.”humane treatment.”

Animals may not be subjected to Animals may not be subjected to “pain or stress” when an “pain or stress” when an alternative procedure is available.alternative procedure is available.

Ethical Issues in Ethical Issues in ResearchResearch

Respecting the rights of human Respecting the rights of human research participants involves:research participants involves: Informed consentInformed consent is an explanation of a is an explanation of a

study and the responsibilities of study and the responsibilities of experimenter and participant.experimenter and participant.

ConfidentialityConfidentiality of study information must of study information must be maintained.be maintained.

DebriefingDebriefing refers to explaining the research refers to explaining the research process to the participants at the end of the process to the participants at the end of the study.study.

DeceptionDeception involving participants must involving participants must be justified.be justified.

Animal research must be justified and Animal research must be justified and must minimize discomfort and painmust minimize discomfort and pain..

Modern Psychology Modern Psychology ViewsViews

• Psychoanalytic viewPsychoanalytic view emphasizes the emphasizes the unconscious mindunconscious mind

• BehaviorismBehaviorism focuses on objective and focuses on objective and measurable behaviorsmeasurable behaviors

• Humanistic psychologyHumanistic psychology emphasizes the emphasizes the inner-self and the importance of inner-self and the importance of subjective feelingssubjective feelings

• Cognitive psychologyCognitive psychology focuses on mental focuses on mental function and reasoningfunction and reasoning

Modern Psychology Modern Psychology ViewsViews

• PsychobiologyPsychobiology views behavior as views behavior as reflecting brain processesreflecting brain processes

• Evolutionary psychologyEvolutionary psychology asserts asserts that certain behavioral that certain behavioral characteristics are subject to characteristics are subject to natural selectionnatural selection

• Cultural psychologyCultural psychology examines the examines the influence of culture and ethnic influence of culture and ethnic practice on people’s behaviorpractice on people’s behavior

Take Home ConceptsTake Home Concepts HypothesisHypothesis What type of study?What type of study?

experimental, correlational, naturalistic experimental, correlational, naturalistic observation, case studyobservation, case study

Independent variable(s) (IV)Independent variable(s) (IV) Dependent variable(s) (DV)Dependent variable(s) (DV) Control groupControl group Were participants randomly sampledWere participants randomly sampled and assigned?and assigned? Ethical concernsEthical concerns Potential experimenter and participant biasPotential experimenter and participant bias