The Science of Psychology

The Science of Psychology Psychology: A Concise Introduction2nd Edition Richard Griggs Chapter 1 Prepared byJ. W. Taylor V

Psychology • The science of behavior and mental processes • Psychologists attempt to understand 1. Observable behavior: Such as speech and physical movement 2. Mental processes: Such as remembering and thinking, which cannot be directly observed

The Journey… • The Four Major Research Perspectives • Research Methods Used by Psychologists • How to Understand Research Results

The Four Major Research Perspectives Perspectives Emphasizing Internal Factors Perspectives Emphasizing External Factors

Four Perspectives Biological Behavioral Cognitive Socio-cultural All four perspectives are complementary; they fit together like the pieces of a jigsaw puzzle to give us the complete picture. No one perspective is “better’ than another, as each one provides information of behavior and mental processing.

Perspectives Emphasizing Internal Factors • Biological perspective • Views our physiological hardware (especially the brain and nervous system) as the major determinants of behavior and mental processing • Cognitive perspective • Emphasizes how our mental processes, such as perception, memory, and problem solving, work and impact our behavior

The Biological Perspective • There are many reasons why people get depressed • From a biological perspective, we would focus on a deficiency of activity for certain chemicals in our nervous system as the cause of this disorder, and use anti-depressant drugs to alleviate the disorder • A few weeks after starting to ingest the drugs, we feel better because mood is in part a function of brain chemistry

The Biological Perspective • Biological psychologists also study the involvement of the various parts of the brain and nervous system on our behavior and mental processing • For instance, vision is actually processed in the back of our heads (hence, we really do have eyes in the back of our heads,” or more precisely “the back of our brains”)

The Cognitive Perspective • When explaining why people become depressed, the cognitive psychology would focus on reasons such as how people explain their successes and failures • If we blame ourselves for all of our setbacks (i.e., make internal attributions), we might start to feel poorly about ourselves • However, if we realize the situation played a role in some of our setbacks (i.e., make external attributions), we might not feel so badly • Of course, it is important for students not to blame their academic failures on their teachers, because in so doing they would fail to take personal responsibility for their lives!

The Cognitive Perspective • Many people report problems remembering other people’s names • Often, we claim it is because we have bad memories, but is that so? • Or, is it that we never bothered to exert the mental energy required in the first place to encode other people’s names? • Both explanations may have validity, and such explanations would be of interest to a cognitive psychologist

Perspectives Emphasizing External Factors • Behavioral perspective • Explains that we behave as we do because of our past history of conditioning by our environment • Sociocultural perspective • Focuses on the impact of other people and culture on our behavior and mental processing

Behavioral Perspective Two types of conditioning: ClassicalConditioning OperantConditioning Can explain how we learn fear and other emotional responses, taste aversions, and certain other behaviors Involves the relationship between our behavior and its environmental consequences

Classical Conditioning • When entering a department store, you may catch the scent of a perfume or cologne of an old boyfriend or girlfriend, and instantly be reminded of that person because during the relationship, you came to associate the scent with the person

Operant Conditioning • If you ask a question in class, and the teacher say “What a stupid question!” you are unlikely to ask questions in the future to avoid such an undesirable consequence • But, if the teachers prefaces his or her response to the question with “That’s an interesting question,” you may continue to ask questions in the future because of the desirable consequence of being implicitly told you are smart

The Sociocultural Perspective • In 1964, Kitty Genovese was brutally attacked and murdered while trying to enter her apartment building in New York City late one night. Many of the people living in the building heard her screams and cries for help, but no one called the police under after the attacker had killed her and fled more than 30 minutes later. • Subsequently, researchers devised laboratory experiments that examined how particular variables influence people’s decision whether or not to help each other.

Major Research Perspectivesin Psychology

Research Methods Used by Psychologists Descriptive Methods Correlational Studies Experimental Research

Research Methods Correlational Descriptive Experimental

Descriptive Methods • Include • Observational techniques • Case studies • Survey research • Seek to provide objective and detailed descriptions of behavior and mental processes

Descriptive Methods:Observational Techniques • The researcher directly observes the behavior of interest • Naturalistic observation: The behavior being observed occurs in its natural setting, without the researcher intervening in the behavior being observed. • Participant observation: The observer becomes part of the group being observed. This type of research is similar to undercover police work.

Naturalistic Observation • Researchers use naturalistic observation when they are interested in how humans or other animals behave in their natural environments • For instance, two well-known observational studies were done by Dian Fossey in a study of mountain gorillas in Africa, and Jane Goodall’s study of chimpanzees in Africa • This technique is also used in settings such as schools, the workplace, and bars

Participant Observation • In most observational studies, the observer begins the study as a participant, whether in a laboratory or a natural setting • One famous example of participant observation was conducted by Rosenhan (1973). In this study, psychologists posing as patients with symptoms of a major mental disorder were admitted to psychiatric hospitals because the doctors could not tell the psychologists from the real disordered patients. Once admitted, these “pseudopatients” acted normally and asked to be released. However, they were not released until many days later!

Descriptive Methods:Case Studies • The researcher studies an individual in depth over an extended period of time to attempt to learn as much as possible about the individual being studied • Often used in clinical settings to gather information that will help in the treatment of the patient • Results of case studies cannot be generalized to other people

Descriptive Methods:Case Studies • Case studies do allow the researcher to develop hypotheses that can be tested using experimental research • For instance, the case of H. M., who had his hippocampus removed for medical reasons at a young age, was a case study. H. M. seemed to have normal memory for information learned before the surgery, but didn’t seem to be able to form any new memories. Such a finding led to the hypothesis that the hippocampus plays an important role in the formation of new memories, which was supported by subsequent experimental research.

Descriptive Methods:Survey Research • Uses questionnaires and interviews to collect information about the behavior, beliefs, and attitudes of particular groups of people • It is critical to note that the wording, order, and structure of the survey questions may lead the participants to biased answers • For instance, some questions might evoke socially-desirable responses in an effort to make certain impressions on the researchers

Descriptive Methods:Survey Research • Another concern for survey researchers is defining the population, or the entire group of people to be studied • From that population, a representative sample, or subset of the people in the population, is surveyed • The sample must be representative of the larger relevant population so you can generalize results of the survey from the smaller sample to the larger population

A representative sample? • In a study of women and love, a sample was drawn mainly from women’s organizations and political groups, plus some women who requested and completed a survey following the researcher’s talk show appearances • Thus, the results (which said that women having affairs and being disenchanted in their relationships with men was typical) were not representative of the population of American women

Random Sampling • Each individual in the population has an equal opportunity of being in the sample • It is much like drawing names from a hat • Random sampling allows the researcher to generalize his or her findings from the sample to the larger population

Correlational Methods • Two variables are measured to determine if they are related • A variable is any factor that can take on more than one value (e.g., height, age, GPA, extraversion level)

The Correlation Coefficient • A statistic that tells us the type and the strength of the relationship between two variables • Range in value from -1.0 to +1.0 • The sign of the coefficient (- or +) tells us the type of relationship, positive or negative

Positive Correlation • A positive correlation indicates a direct relationship between two variables, with low scores on one variable tending to be paired with low scores on the other variable, and high scores on one variable tending to be paired with high scores on the other variable • For instance, SAT scores and first-year college GPA tend to be positively correlated • A person’s height and weight also tend to be positively correlated

Negative Correlation • A negative correlation is an inverse relationship between two variables, with low scores on one variable tending to be paired with high scores on the other variable • For instance, there is a negative correlation between how much time a student watches TV and his or her grades in school • Mountain elevation level and temperature are also negatively correlated

Strength of Relationship • The second part of the correlation coefficient is its absolute value, which ranges from 0 to 1 • Zero and absolute values near zero indicate no relationship • As the absolute value increases toward 1.0, the strength of the relationship increases • It is critical to note that the sign of the coefficient tells us nothing about the strength of the relationship

Scatterplots • A scatterplot is a visual depiction of correlational data • On the X axis are scores on one variable; on the Y axis are scores on the second variable • Each data point in the scatterplot is a person’s scores on each of the two variables

The Third-Variable Problem • Strong correlations give us excellent predictability, but they do not allow us to draw cause-and-effect conclusions about the relationships between the two variables • Thethird-variable problem occurs when a third, unmeasured variable is responsible for the relationship observed between the two measured variables • For example, the length of time a man is married is negatively correlated with the amount of hair on his head • Does this mean that being married longer causes a man’s hair to fall out?

Experimental Research • The key aspect of experimental research is that the researcher controls the experimental setting • It is this control that allows the researcher to make cause-and-effect statements about the experimental results

Experimental Control • First, the experimenter controls for the influence of possible third-variables by making sure that they are held constant across all of the experimental groups/conditions • Second, the experimenter controls for any possible influence due to the individual characteristics of the participants, such as intelligence, by usingrandom assignment, which is randomly assigning the participants to groups in an experiment to equalize participant characteristics across the various groups in the experiment

Designing an Experiment • When a researcher designs an experiment, the researcher begins with a hypothesis about the cause-and-effect relationship between two variables • One of the variables is assumed to be the cause, and the other variable is the one to be affected • Theindependent variable is the hypothesized cause, and the experimenter manipulates it • Thedependent variable is the variable that is hypothesized to be affect by the independent variable and thus is measured by the experimenter

Designing an Experiment • The simplest of experiments is one with two groups, in which participants are randomly assigned to one of the groups • One of the groups will be exposed to the independent variable, and the other group will not be • The group exposed to the independent variable is called the experimental group • The group not exposed to the independent variable is called the control group

For example… • If the hypothesis is that aerobic exercise reduces anxiety, then the independent variable to be manipulated is aerobic exercise, and the dependent variable will be anxiety level • The experimental group will participate in some aerobic exercise program, and the control group will not • The experiment must measure the anxiety levels for the groups at the beginning of the study before the independent variable is manipulated and then again after the manipulation • If the two groups are truly equivalent, the average anxiety level for each group at the start of the study should be the same • If aerobic exercise does reduce anxiety, then we should see this difference in the second measurement at the end of the experiment

The Placebo Group • In addition to the experimental and control groups, we need to add a placebo group to improve the experiment • A placebo group is a group of participants that believes they are receiving treatment but are not • They receive a placebo, a harmless pill that has no active ingredients • For example, this group would be told they are getting an anti-anxiety drug, but they would only get a placebo

The Placebo Group • The placebo effect is improvement due to the expectation of improving because of receiving treatment • The reduction of anxiety in the experimental group participants may, in fact, be partially or completely due to a placebo effect • To conclude that the reduction of anxiety in the experimental group was not due to a placebo effect, it would have to be significantly greater than that observed for the placebo group

Inferential Statistical Analyses • Indicate the probability that the results of a study are due to random variation (chance) • Of course, the researchers would want this probability to be low • In statistics, a “significant” finding is one that has a probability less than 0.05 (1/20) that it is due to chance • Thus, a significant finding is one that is not likely due to chance

The Double-Blind Procedure • A control measure in which neither the experimenter nor the participants know which participants actually got the treatment and or got the placebo • Controls for experimenter expectations • If the experimenter knew which condition the participants were in, then s/he might unintentionally treat them differently and thereby impact their behavior

Summary of Research Methods

The Science of Psychology