reporting the study’s purpose, design, and methods prior to observing its results. If the results show a treatment to be ineffective, then other researchers would have access to that important information (Nosek & Lindsay, 2018).
Review
Pseudoscience consists of statements, beliefs, and practices that seem to be based on empirical evidence but are actually incompatible with scientific thinking. It capitalizes on our inherent cognitive and emotional biases.
Science is a set of principles and procedures used to understand the natural world. It relies on careful, systematic collection of empirical data rather than expectations, emotions, or casual observations.
Science is characterized by (1) falsifiability, (2) critical thinking, (3) parsimony, (4) precision, and (5) reproducibility.
What Is the Scientific Method?
In addition to the five core principles of scientific thinking, psychological scientists also follow the scientific method: procedures used to gather, evaluate, and organize information about the natural world (Figure 3.1).
At the heart of the scientific method is a theory. A psychological theory is an integrated set of ideas that explain and predict broad aspects of human behavior or development. For example, Jean Piaget (1964) developed a theory of cognitive development in which children progress through four discrete stages from infancy to adulthood. Piaget’s theory organizes our understanding of cognitive abilities across the lifespan and allows us to make predictions about the problem-solving skills of children at various ages.
Similarly, Albert Bandura (1978) developed social learning theory. He believed that children model the behavior of other people, especially when those people are reinforced for acting a certain way. Bandura’s theory organizes our knowledge about the way children learn information and acquire new skills. It lets us predict how children might act when exposed to certain types of models, such as violent video game characters or prosocial peers.
Theories are usually too broad and abstract to test in a single research study. So, scientists develop hypotheses about one or more parts of the theory. A hypothesis is a specific, falsifiable prediction about the relationship between two or more variables. For example, a researcher might hypothesize that children who play violent video games will be more likely to show aggression than children who do not play violent video games. The researcher’s hypothesis tests one aspect of social learning theory, namely, that exposure to violent games will increase children’s likelihood of aggression.
Figure 3.1 ■ The Scientific Method
Note: Psychologists use the scientific method to gather, evaluate, and organize information about human behavior and development.
Scientists use empirical data to test hypotheses. Empirical data refer to information gathered through our senses. Psychologists might observe children during class or recess, ask their parents to complete rating scales about children’s behavior at home, or administer tests to assess children’s intelligence or personality. Scientists do not rely on information from nonempirical sources, such as their personal beliefs, feelings, or the opinions of people in authority.
In order to test a hypothesis using empirical data, researchers must operationally define each variable in the study. An operational definition specifies how each variable will be measured. For example, a researcher might operationally define a child’s “exposure to violent video games” as the number of games the child owns that are rated Mature or Adults Only by the Entertainment Software Rating Board. Similarly, the researcher might operationally define “aggression” as the number of times in the past year the child engaged in pushing, shoving, hitting, or physical fighting at school.
After collecting data, researchers will analyze and interpret their findings. If the results of the study support the researchers’ hypotheses, then they can have greater confidence in the theory upon which their hypotheses are based. Ideally, the researchers will try to replicate their study to see if their findings are reproducible and can be applied to different people or situations.
If the results of the study do not support the researchers’ hypotheses, the researchers may need to modify their theory. Even unsuccessful studies are important because they can help to improve theories and build a better understanding of children’s behavior and development.
Review
The scientific method is a characteristic set of procedures used to gather, evaluate, and organize empirical data about the natural world.
Psychological scientists generate and test specific, falsifiable hypotheses based on broader theories regarding behavior and development.
Scientists rely on empirical data to test hypotheses. They operationally define constructs so they can measure them with greater precision and so other scientists can reproduce their findings.
3.2 Research Goals and Methods
Psychological research has four broad goals: (1) description, (2) prediction, (3) explanation, and (4) replication. Psychologists use different methods to accomplish each goal. For example, a psychologist who wants to describe the essential characteristics of ADHD might use a case study or survey, whereas a psychologist interested in explaining how stimulant medication reduces children’s ADHD symptoms would likely conduct an experiment. In this section, we will examine some of the most common research methods used in the field of abnormal child psychology.
How Do Psychologists Describe Behavior?
Case Studies
A case study is a detailed description of a person, group, or phenomenon. Researchers who conduct case studies provide as much detail as possible about the person’s background, current functioning, and other relevant aspects of his or her life. Case studies may also describe the person’s development or response to treatment. Case studies focus on idiographic assessment—that is, they assess a person’s unique abilities, experiences, and behaviors (Fishman, 2018b).
Case studies are especially useful to describe new disorders. For example, in 1932, two German doctors named Franz Kramer and Hans Pollnow described children with a new condition that they called “hyperkinetic disease” (Lange, Reichl, Lange, Tucha, & Tucha, 2010). The children had no history of injury or illness, yet their behavior caused problems at home and school. Their most striking feature was their hyperactivity:
These children cannot sit still for a second. They run up and down the room, climb about preferring high furniture in particular, and are displeased when deterred from acting out their motor impulses. They indiscriminately touch or move everything available without pursuing a goal.
From Science to Practice: A Cure for Headaches
In 1937, a young pediatrician named Charles Bradley was treating a boy with chronic headaches (Strohl, 2011). When traditional treatments failed, Bradley tried to alleviate the boy’s headaches using a new stimulant medication called Benzedrine. Although Benzedrine had little effect on the boy’s headaches, it caused an immediate and dramatic increase in the boy’s attention and academic performance. Bradley decided to test the medication with other children and described their response:
The most spectacular change in behavior brought about by the use of Benzedrine was the remarkably improved school performance of about half the children. They were more interested in their work and performed it more quickly and accurately. In addition, they