The Stanford Prison Study
This study by Phillip Zimbardo is another classic study that all psychology students should know.
To see Zimbardo explain a little about the experiment watch this trailer: http://www.youtube.com/watch?v=RKW_MzREPp4 (2 min)
However, for some original footage of the experiment itself go to this website (Class, note that some of this footage is very disturbing, and you do not have to watch this video if it disturbs you. Instead, read the next article below) http://www.youtube.com/watch?v=sZwfNs1pqG0 (14 minutes)
Forty years later, the participants in the Zimbardo experiment are interviewed and reflect on the experiment: http://www.stanfordalumni.org/news/magazine/2011/julaug/features/spe.html
Answer the following questions:
What happened?
What did you learn?
Were you surprised at the results of the study?
Was the study ethical? Should this study have been conducted?
Does Zimbardo’s study apply to the Abu Ghraib Prison (answer optional for this one)?
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Chapter 2
Psychological Science
Psychologists study the behavior of both humans and animals, and the main purpose of this
research is to help us understand people and to improve the quality of human lives. The results of
psychological research are relevant to problems such as learning and memory, homelessness,
psychological disorders, family instability, and aggressive behavior and violence. Psychological
research is used in a range of important areas, from public policy to driver safety. It guides court
rulings with respect to racism and sexism (Brown v. Board of Education, 1954; Fiske, Bersoff,
Borgida, Deaux, & Heilman, 1991), [1]
as well as court procedure, in the use of lie detectors
during criminal trials, for example (Saxe, Dougherty, & Cross, 1985). [2]
Psychological research
helps us understand how driver behavior affects safety (Fajen & Warren, 2003), [3]
which
methods of educating children are most effective (Alexander & Winne, 2006; Woolfolk-Hoy,
2005), [4]
how to best detect deception (DePaulo et al., 2003), [5]
and the causes of terrorism
(Borum, 2004). [6]
Some psychological research is basic research. Basic research is research that answers
fundamental questions about behavior. For instance, biopsychologists study how nerves conduct
impulses from the receptors in the skin to the brain, and cognitive psychologists investigate how
different types of studying influence memory for pictures and words. There is no particular
reason to examine such things except to acquire a better knowledge of how these processes
occur. Applied research is research that investigates issues that have implications for everyday
life and provides solutions to everyday problems. Applied research has been conducted to study,
among many other things, the most effective methods for reducing depression, the types of
advertising campaigns that serve to reduce drug and alcohol abuse, the key predictors of
managerial success in business, and the indicators of effective government programs, such as
Head Start.
Basic research and applied research inform each other, and advances in science occur more
rapidly when each type of research is conducted (Lewin, 1999). [7]
For instance, although research
concerning the role of practice on memory for lists of words is basic in orientation, the results
could potentially be applied to help children learn to read. Correspondingly, psychologist-
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practitioners who wish to reduce the spread of AIDS or to promote volunteering frequently base
their programs on the results of basic research. This basic AIDS or volunteering research is then
applied to help change people’s attitudes and behaviors.
The results of psychological research are reported primarily in research articles published in
scientific journals, and your instructor may require you to read some of these. The research
reported in scientific journals has been evaluated, critiqued, and improved by scientists in the
field through the process of peer review. In this book there are many citations to original
research articles, and I encourage you to read those reports when you find a topic interesting.
Most of these papers are readily available online through your college or university library. It is
only by reading the original reports that you will really see how the research process works.
Some of the most important journals in psychology are provided here for your information.
Psychological Journals
The following is a list of some of the most important journals in various subdisciplines of psychology. The research
articles in these journals are likely to be available in your college library. You should try to read the primary source
material in these journals when you can.
General Psychology
American Journal of Psychology
American Psychologist
Behavioral and Brain Sciences
Psychological Bulletin
Psychological Methods
Psychological Review
Psychological Science
Biopsychology and Neuroscience
Behavioral Neuroscience
Journal of Comparative Psychology
Psychophysiology
Clinical and Counseling Psychology
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Journal of Abnormal Psychology
Journal of Consulting and Clinical Psychology
Journal of Counseling Psychology
Cognitive Psychology
Cognition
Cognitive Psychology
Journal of Experimental Psychology
Journal of Memory and Language
Perception & Psychophysics
Cross-Cultural, Personality, and Social Psychology
Journal of Cross-Cultural Psychology
Journal of Experimental Social Psychology
Journal of Personality
Journal of Personality and Social Psychology
Personality and Social Psychology Bulletin
Developmental Psychology
Child Development
Developmental Psychology
Educational and School Psychology
Educational Psychologist
Journal of Educational Psychology
Review of Educational Research
Environmental, Industrial, and Organizational Psychology
Journal of Applied Psychology
Organizational Behavior and Human Decision Processes
Organizational Psychology
Organizational Research Methods
Personnel Psychology
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In this chapter you will learn how psychologists develop and test their research ideas; how they
measure the thoughts, feelings, and behavior of individuals; and how they analyze and interpret
the data they collect. To really understand psychology, you must also understand how and why
the research you are reading about was conducted and what the collected data mean. Learning
about the principles and practices of psychological research will allow you to critically read,
interpret, and evaluate research.
In addition to helping you learn the material in this course, the ability to interpret and conduct
research is also useful in many of the careers that you might choose. For instance, advertising
and marketing researchers study how to make advertising more effective, health and medical
researchers study the impact of behaviors such as drug use and smoking on illness, and computer
scientists study how people interact with computers. Furthermore, even if you are not planning a
career as a researcher, jobs in almost any area of social, medical, or mental health science require
that a worker be informed about psychological research.
[1] Brown v. Board of Education, 347 U.S. 483 (1954); Fiske, S. T., Bersoff, D. N., Borgida, E., Deaux, K., & Heilman, M. E. (1991).
Social science research on trial: Use of sex stereotyping research in Price Waterhouse v. Hopkins. American Psychologist, 46(10),
1049–1060.
[2] Saxe, L., Dougherty, D., & Cross, T. (1985). The validity of polygraph testing: Scientific analysis and public
controversy. American Psychologist, 40, 355–366.
[3] Fajen, B. R., & Warren, W. H. (2003). Behavioral dynamics of steering, obstacle avoidance, and route selection. Journal of
Experimental Psychology: Human Perception and Performance, 29(2), 343–362.
[4] Alexander, P. A., & Winne, P. H. (Eds.). (2006). Handbook of educational psychology(2nd ed.). Mahwah, NJ: Lawrence
Erlbaum Associates; Woolfolk-Hoy, A. E. (2005).Educational psychology (9th ed.). Boston, MA: Allyn & Bacon.
[5] DePaulo, B. M., Lindsay, J. J., Malone, B. E., Muhlenbruck, L., Charlton, K., & Cooper, H. (2003). Cues to
deception. Psychological Bulletin, 129(1), 74–118.
[6] Borum, R. (2004). Psychology of terrorism. Tampa: University of South Florida.
[7] Lewin, K. (1999). The complete social scientist: A Kurt Lewin reader (M. Gold, Ed.). Washington, DC: American Psychological
Association.
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2.1 Psychologists Use the Scientific Method to Guide Their Research L E A R N I N G O B J E C T I V E S
1. Describe the principles of the scientific method and explain its importance in conducting and interpreting research.
2. Differentiate laws from theories and explain how research hypotheses are developed and tested.
3. Discuss the procedures that researchers use to ensure that their research with humans and with animals is ethical.
Psychologists aren’t the only people who seek to understand human behavior and solve social
problems. Philosophers, religious leaders, and politicians, among others, also strive to provide
explanations for human behavior. But psychologists believe that research is the best tool for
understanding human beings and their relationships with others. Rather than accepting the claim
of a philosopher that people do (or do not) have free will, a psychologist would collect data to
empirically test whether or not people are able to actively control their own behavior. Rather
than accepting a politician’s contention that creating (or abandoning) a new center for mental
health will improve the lives of individuals in the inner city, a psychologist would empirically
assess the effects of receiving mental health treatment on the quality of life of the recipients. The
statements made by psychologists are empirical, which means they are based on systematic
collection and analysis of data.
The Scientific Method
All scientists (whether they are physicists, chemists, biologists, sociologists, or psychologists)
are engaged in the basic processes of collecting data and drawing conclusions about those data.
The methods used by scientists have developed over many years and provide a common
framework for developing, organizing, and sharing information. The scientific method is the set
of assumptions, rules, and procedures scientists use to conduct research.
In addition to requiring that science be empirical, the scientific method demands that the
procedures used be objective, or free from the personal bias or emotions of the scientist. The
scientific method proscribes how scientists collect and analyze data, how they draw conclusions
from data, and how they share data with others. These rules increase objectivity by placing data
under the scrutiny of other scientists and even the public at large. Because data are reported
objectively, other scientists know exactly how the scientist collected and analyzed the data. This
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means that they do not have to rely only on the scientist’s own interpretation of the data; they
may draw their own, potentially different, conclusions.
Most new research is designed to replicate—that is, to repeat, add to, or modify—previous
research findings. The scientific method therefore results in an accumulation of scientific
knowledge through the reporting of research and the addition to and modifications of these
reported findings by other scientists.
Laws and Theories as Organizing Principles
One goal of research is to organize information into meaningful statements that can be applied in
many situations. Principles that are so general as to apply to all situations in a given domain of
inquiry are known as laws. There are well-known laws in the physical sciences, such as the law
of gravity and the laws of thermodynamics, and there are some universally accepted laws in
psychology, such as the law of effect and Weber’s law. But because laws are very general
principles and their validity has already been well established, they are themselves rarely directly
subjected to scientific test.
The next step down from laws in the hierarchy of organizing principles is theory. A theory is an
integrated set of principles that explains and predicts many, but not all, observed relationships
within a given domain of inquiry. One example of an important theory in psychology is the stage
theory of cognitive development proposed by the Swiss psychologist Jean Piaget. The theory
states that children pass through a series of cognitive stages as they grow, each of which must be
mastered in succession before movement to the next cognitive stage can occur. This is an
extremely useful theory in human development because it can be applied to many different
content areas and can be tested in many different ways.
Good theories have four important characteristics. First, good theories are general, meaning they
summarize many different outcomes. Second, they are parsimonious, meaning they provide the
simplest possible account of those outcomes. The stage theory of cognitive development meets
both of these requirements. It can account for developmental changes in behavior across a wide
variety of domains, and yet it does so parsimoniously—by hypothesizing a simple set of
cognitive stages. Third, good theories provide ideas for future research. The stage theory of
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cognitive development has been applied not only to learning about cognitive skills, but also to
the study of children’s moral (Kohlberg, 1966) [1]
and gender (Ruble & Martin,
1998) [2]
development.
Finally, good theories are falsifiable (Popper, 1959), [3]
which means the variables of interest can
be adequately measured and the relationships between the variables that are predicted by the
theory can be shown through research to be incorrect. The stage theory of cognitive
development is falsifiable because the stages of cognitive reasoning can be measured and
because if research discovers, for instance, that children learn new tasks before they have
reached the cognitive stage hypothesized to be required for that task, then the theory will be
shown to be incorrect.
No single theory is able to account for all behavior in all cases. Rather, theories are each limited
in that they make accurate predictions in some situations or for some people but not in other
situations or for other people. As a result, there is a constant exchange between theory and data:
Existing theories are modified on the basis of collected data, and the new modified theories then
make new predictions that are tested by new data, and so forth. When a better theory is found, it
will replace the old one. This is part of the accumulation of scientific knowledge.
The Research Hypothesis
Theories are usually framed too broadly to be tested in a single experiment. Therefore, scientists
use a more precise statement of the presumed relationship among specific parts of a theory—a
research hypothesis—as the basis for their research. A research hypothesis is a specific and
falsifiable prediction about the relationship between or among two or more variables, where
a variable is any attribute that can assume different values among different people or across
different times or places. The research hypothesis states the existence of a relationship between
the variables of interest and the specific direction of that relationship. For instance, the research
hypothesis ―Using marijuana will reduce learning‖ predicts that there is a relationship between a
variable ―using marijuana‖ and another variable called ―learning.‖ Similarly, in the research
hypothesis ―Participating in psychotherapy will reduce anxiety,‖ the variables that are expected
to be related are ―participating in psychotherapy‖ and ―level of anxiety.‖
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When stated in an abstract manner, the ideas that form the basis of a research hypothesis are
known as conceptual variables. Conceptual variables are abstract ideas that form the basis of
research hypotheses. Sometimes the conceptual variables are rather simple—for instance, ―age,‖
―gender,‖ or ―weight.‖ In other cases the conceptual variables represent more complex ideas,
such as ―anxiety,‖ ―cognitive development,‖ ―learning,‖ self-esteem,‖ or ―sexism.‖
The first step in testing a research hypothesis involves turning the conceptual variables
into measured variables, which are variables consisting of numbers that represent the conceptual
variables. For instance, the conceptual variable ―participating in psychotherapy‖ could be
represented as the measured variable ―number of psychotherapy hours the patient has accrued‖
and the conceptual variable ―using marijuana‖ could be assessed by having the research
participants rate, on a scale from 1 to 10, how often they use marijuana or by administering a
blood test that measures the presence of the chemicals in marijuana.
Psychologists use the term operational definition to refer to a precise statement of how a
conceptual variable is turned into a measured variable. The relationship between conceptual and
measured variables in a research hypothesis is diagrammed in Figure 2.1 “Diagram of a Research
Hypothesis”. The conceptual variables are represented within circles at the top of the figure, and
the measured variables are represented within squares at the bottom. The two vertical arrows,
which lead from the conceptual variables to the measured variables, represent the operational
definitions of the two variables. The arrows indicate the expectation that changes in the
conceptual variables (psychotherapy and anxiety in this example) will cause changes in the
corresponding measured variables. The measured variables are then used to draw inferences
about the conceptual variables.
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Figure 2.1 Diagram of a Research Hypothesis
In this research hypothesis, the conceptual variable of attending psychotherapy is operationalized using the number
of hours of psychotherapy the client has completed, and the conceptual variable of anxiety is operationalized using
self-reported levels of anxiety. The research hypothesis is that more psychotherapy will be related to less reported
anxiety.
Table 2.1 “Examples of the Operational Definitions of Conceptual Variables That Have Been
Used in Psychological Research” lists some potential operational definitions of conceptual
variables that have been used in psychological research. As you read through this list, note that in
contrast to the abstract conceptual variables, the measured variables are very specific. This
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specificity is important for two reasons. First, more specific definitions mean that there is less
danger that the collected data will be misunderstood by others. Second, specific definitions will
enable future researchers to replicate the research.
Table 2.1 Examples of the Operational Definitions of Conceptual Variables That Have Been Used in Psychological
Research
Conceptual variable Operational definitions
Aggression
Number of presses of a button that administers shock to another student
Number of seconds taken to honk the horn at the car ahead after a stoplight turns green
Interpersonal attraction
Number of inches that an individual places his or her chair away from another person
Number of millimeters of pupil dilation when one person looks at another
Employee satisfaction
Number of days per month an employee shows up to work on time
Rating of job satisfaction from 1 (not at all satisfied) to 9 (extremely satisfied)
Decision-making skills
Number of groups able to correctly solve a group performance task
Number of seconds in which a person solves a problem
Depression
Number of negative words used in a creative story
Number of appointments made with a psychotherapist
Conducting Ethical Research
One of the questions that all scientists must address concerns the ethics of their research.
Physicists are concerned about the potentially harmful outcomes of their experiments with
nuclear materials. Biologists worry about the potential outcomes of creating genetically
engineered human babies. Medical researchers agonize over the ethics of withholding potentially
beneficial drugs from control groups in clinical trials. Likewise, psychologists are continually
considering the ethics of their research.
Research in psychology may cause some stress, harm, or inconvenience for the people who
participate in that research. For instance, researchers may require introductory psychology
students to participate in research projects and then deceive these students, at least temporarily,
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about the nature of the research. Psychologists may induce stress, anxiety, or negative moods in
their participants, expose them to weak electrical shocks, or convince them to behave in ways
that violate their moral standards. And researchers may sometimes use animals in their research,
potentially harming them in the process.
Decisions about whether research is ethical are made using established ethical codes developed
by scientific organizations, such as the American Psychological Association, and federal
governments. In the United States, the Department of Health and Human Services provides the
guidelines for ethical standards in research. Some research, such as the research conducted by the
Nazis on prisoners during World War II, is perceived as immoral by almost everyone. Other
procedures, such as the use of animals in research testing the effectiveness of drugs, are more
controversial.
Scientific research has provided information that has improved the lives of many people.
Therefore, it is unreasonable to argue that because scientific research has costs, no research
should be conducted. This argument fails to consider the fact that there are significant costs
to not doing research and that these costs may be greater than the potential costs of conducting the
