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21
Psychology Questions
Why conduct research in psychology?
We don’t always know how people will think or behave.
Can you anticipate the results of some research questions?
Answer “true” or “false” to the following statements.
1. Mothers talk to their younger children differently than they talk to their
older children. True or false?
2. Few students will confess to ruining a computer program if they didn’t do
it. True or false?
3. Most individuals will notice if a person they are talking to is replaced by
another person. True or false?
4. Writing about adjusting to college improves students’ grades. True or
false?
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Answers to Psychology Questions
1. Mothers talk to their younger children differently than they talk to their
older children. True or false?
2. Few students will confess to ruining a computer program if they didn’t do
it. True or false?
3. Most individuals will notice if a person they are talking to is replaced by
another person. True or false?
4. Writing about adjusting to college improves students’ grades. True or
false?
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References
1. How mothers speak with their children:
Haden, C. A. (1998). Reminiscing with different children: Relating maternal
stylistic consistency and sibling similarity in talk about the past.
Developmental Psychology, 34, 99—114.
2. False confessions:
Kassin, S. A., & Kiechel, K. L. (1996). The social psychology of false
confessions: Compliance, internalization, and confabulation.
Psychological Science, 7, 125-128.
3. Failure to notice a conversation partner has changed:
Simons, D. J., & Levin, D. T. (1998). Failure to detect changes to people
during a real-world interaction. Psychonomic Bulletin and Review, 5,
644-649.
4. Writing and adjustment to college:
Pennebaker, J. W., & Francis, M. E. (1996). Cognitive, emotional, and
language processes in disclosure. Cognition and Emotion, 10, 601-626.
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The Scientific Method
• Way to gain knowledge about behavior and mental processes
Approaches to Gaining Knowledge
Nonscientific (Everyday) Scientific
General Approach Intuitive, uncritical Empirical,
and Attitude accepting critical, skeptical
Observation Casual, Systematic,
uncontrolled controlled
Concepts Ambiguous Clear definitions
Reporting Biased, Unbiased
subjective objective
Instruments Inaccurate, Accurate
imprecise precise
Measurement Not valid nor Valid and
reliable reliable
Hypotheses Untestable Testable
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Scientific Observation
• Systematic and controlled
▪ Control: essential ingredient of science
▪ Greatest control: experiment
• Features of an experiment
▪ Manipulate (control) one or more factors → independent variable
▪ Observe effects of manipulation on behavior → dependent variables
• Independent Variable (IV)
▪ Must have at least two conditions or levels
o Treatment condition
o Control condition
• Dependent Variable (DV)
▪ Measures of the effects of the IV
• The word “experiment” is often used in everyday language to mean the
same thing as “research,” but the word experiment refers to a very
specific type of research study.
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Independent Variables and Dependent Variables
Read the following descriptions of research and identify the independent
and dependent variables:
1. In the Pennebaker and Francis (1996) study on adjustment to college,
students wrote about their emotions associated with beginning college
or they wrote about superficial events that took place during their day.
Pennebaker and Francis obtained information about the participants’
GPA and their frequency of visiting the student health center.
What is the independent variable and what are the dependent variables?
IV: Type of writing: emotional (treatment) and superficial (control)
DVs: GPA and the number of health center visits
2. In a study on factors that influence people’s willingness to help others, a
researcher mimicked (copied) the behavior of participants (e.g., sitting
position, posture) or did not mimic the participants’ behavior. The
researcher then dropped pens and observed whether participants
helped to pick up the pens.
What is the independent variable and what is the dependent variable?
IV: Mimicry: present (treatment) or absent (control)
DV: Whether participants helped by picking up the pens (yes or no)
Constructs and Operational Definitions
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• Construct: concept or idea used to explain behaviors or mental
processes
▪ Examples: aggression, depression, intelligence, memory, personality
• Operational definition: specific procedure used to produce or measure a
construct
▪ Advantages:
o Allow scientists to define specifically what they mean
o Allow clear communication among scientists
▪ Disadvantages:
o A potentially limitless number of operational definitions exists for
any particular construct.
Match the construct with its operational definition:
Construct Operational Definition
Aggression A. score on the Minnesota Multiphasic Personality
Inventory
Depression B. score on the final exam of this course
Intelligence C. number of times person hits another person
Personality D. number of depression symptoms from the Diagnostic
and Statistical Manual
Memory E. score on the Wechsler Adult Intelligence Scale (WAIS)
Knowledge of F. score on the Digit-span Test of memory
research
methods
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Measurement: Validity and Reliability
• Accurate and precise instruments
• Physical measurement
▪ Dimensions have agreed-upon standards and instruments
▪ Examples: length, weight, time
• Psychological measurement
▪ Measure psychological constructs
▪ No agreed-upon standard or instrument
▪ Examples: beauty, intelligence, aggression
▪ Psychologists develop measures to assess these constructs.
• Validity: truthfulness
▪ Measures what it claims to measure
• Reliability: consistency
▪ Example: different observers consistently agree about an observation
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Testable Hypotheses
• Hypothesis: tentative explanation for a phenomenon
• Often stated in the form of a prediction and an explanation for the
prediction
• Scientific hypotheses must be testable.
A hypothesis is not testable if it has any of these three characteristics:
▪ Constructs not adequately defined
▪ Circular—the event itself is used as an explanation of the event
▪ Refers to ideas or forces not recognized by science
30
Goals of Research in Psychology
1. Description Researchers define, classify, catalogue, or categorize
events and their relationships to describe mental
processes and behavior.
2. Prediction When researchers identify correlations (relationships)
among variables they are able to predict mental
processes and behavior.
3. Explanation Researchers understand and can explain a
phenomenon when they can identify its cause(s).
4. Application Psychologists apply their knowledge and research
methods to improve people’s lives.
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Description
Most psychological research is nomothetic rather than idiographic.
• Nomothetic research
▪ Large sample sizes
▪ Describe what is true on average or in general
▪ Emphasize similarities among individuals
• Idiographic research
▪ Intensive study of a single case
▪ Focus on uniqueness
Most psychological research is quantitative rather than qualitative.
• Quantitative research
▪ Statistical summaries and analyses
• Qualitative research
▪ Verbal summaries of research observations
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Prediction
• Statistical correlations between variables allow predictions about
behavior and mental processes
▪ Variable: Dimension on which people differ, or vary.
▪ Examples: childhood loss of a parent (yes/no), symptoms of
depression, aggressiveness, age, stressful life events, physical
illness
• Correlation: Two measures of the same people, events, or things vary
together or go together.
▪ Example: The more stressful life events people experience (one
variable), the more physical illness they are likely to experience (a
second variable).
▪ Positive correlation: As scores on one variable increase, scores on
the second variable increase.
▪ Negative correlation: As scores on one variable increase, scores on
the second variable decrease.
• Prediction: When two variables are correlated, if we know people’s
scores for one variable, we can statistically compute (predict) scores for
the second variable.
• Correlation does not imply causation.
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Explanation
• Conduct experiments to identify the causes of a phenomenon
• Causal inferences: statements about the cause of an event or a
behavior.
Three conditions:
▪ Covariation of events
▪ Time-order relationship
▪ Elimination of plausible alternative causes
• Example of a causal inference:
▪ Exposure to media violence causes an increase in the likelihood of
aggressive and violent thoughts, emotions, and behaviors
immediately after the exposure.
Based on this causal inference, we know that:
▪ Exposure to media violence and aggression covary together.
▪ Aggression follows after the exposure (not before).
▪ Other explanations for the relationship between exposure to media
violence and aggression have been ruled out.
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Confounding
• Two potentially effective independent variables are allowed to vary
together simultaneously
▪ Cannot determine which, if any, variable produced an effect on the
dependent variable.
▪ Causal inference requires no confounding
Describe the confounding in this research example:
A psychologist seeks to demonstrate the effectiveness of a new therapy for
helping students to cope with stress. One group of students receives the
new treatment; a second group of students is placed on a waiting list to
receive the treatment during the next term (control group). To make sure
the students in the control group maintain their interest in the research
project, an assistant calls them every week to “check in and see how
they’re doing.” The psychologist measures the coping of students in both
the treatment and control groups at the end of the term and discovers no
difference in their coping. The researcher decides to abandon the new
therapy.
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Generalization
• Researchers are not simply interested in the one sample of people or
the one set of circumstances they studied.
• They seek to generalize a study’s findings to
▪ Populations
▪ Settings
▪ Conditions beyond those tested in a specific study
• Generalization (also called external validity)
▪ Can we generalize or apply the findings from psychology studies with
college student samples to describe other people?
▪ Can we generalize the findings of highly controlled laboratory studies
to real-world settings?
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Application
Psychologists apply their knowledge and research methods to improve
people’s lives.
• Basic research
▪ Research to understand behavior and mental processes
▪ Develop and test theories about behavior and mental processes
▪ “Knowledge for its own sake”
▪ Most often conducted in laboratory settings
• Applied research
▪ Research to change people’s lives for the better
▪ Often conducted in “real world” or natural settings
• Basic and applied research studies are complementary; both necessary.
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Scientific Theory Construction and Testing
• Theory
Logically organized set of propositions (claims, statements, assertions)
that serves to
▪ Define events (concepts)
▪ Describe relationships among these events
▪ Explain the occurrence of these events
• Scope
Theories differ in the breadth of events they seek to explain, from
specific phenomena (e.g., flashbulb memory) to complex phenomena
(e.g., love).
• Functions
A theory organizes empirical knowledge from previous studies and
guides future research by suggesting testable hypotheses.
• Important Features
Good theories are
▪ Logical
▪ Precise
▪ Parsimonious
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Intervening Variables
• Processes or mechanisms to explain the relationship between an
independent variable and a dependent variable
▪ “Hidden” processes represented by psychological constructs
▪ Example: “thirst”
liquid deprivation liquid consumption
amount of salt thirst effort to obtain liquid
exercise taste of liquid
temperature
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Identifying Intervening Variables
For each of the following, think of an intervening variable that may explain
the relationship:
Independent Variable Intervening Variable Dependent Variable
Presence/absence of ? Aggressive response
an insult
Amount of time spent ? Score on a test
studying
Length of time without ? Amount of water
liquid consumed
Amount of positive feedback ? Improved performance
