factors other than the ones that we originally considered might have influenced our results. By doing this, we come to see that science is a combination of interaction with the world and logic.
The logic of science leads us to the realization that one of the real strengths of science is showing us when we are wrong. If someone says that all swans are white, for example, seeing a white swan—or seeing 500 swans, all of which are white—does not actually prove this to be the case. However, seeing just one black swan would clearly show that the statement was wrong. In this spirit, Einstein is reported to have said, “No amount of experimentation can ever prove me right; a single experiment can prove me wrong.” The philosopher of science Sir Karl Popper referred to this approach as falsification. Thus, one important aspect of doing science is to ask yourself, how would I know if I was wrong?
The methods of science closely parallel our ways of learning about the world. We can think about these in terms of three stages.
First, scientists begin with an idea or expectation. A formally stated expectation is called a hypothesis. The scientist says, “I expect this to happen under these conditions,” and thus states the hypothesis.
Second, scientists look to experience to evaluate the accuracy of their ideas or expectations about the world. That is, they try to find or create the situation that will allow them to observe what they are interested in studying. Through observation and experimentation, scientists can begin to evaluate their ideas and expectations about the world. Learning about the world through observation and experimentation is an example of empiricism.
empiricism: the process of understanding the world through observation and experimentation
Third, on the basis of their observations and experiments, scientists seek to draw conclusions or inferences about their ideas and expectations. They reorganize their ideas and consider the impact of the new information on their theoretical conceptualizations.
Overall, science is a way of determining what we can infer about the world. In its simplest form, the scientific method consists of asking a question about the world and then experiencing the world to determine the answer. When we begin an inquiry, what we already know about our topic leaves us in one of a number of positions. In some cases, we know little about our topic, or our topic may be very complex. Consequently, our ideas and questions are general. For example, how does our memory work? What causes mental illness? What factors make a fruitful marriage? How can we model the brain? Can experience change our brain?
This chapter will focus on the methods of a psychological science. I begin with case study approaches and then move to more experimental approaches. These include correlational approaches and more formal experimental designs. The chapter ends with a consideration of ethics as applied to research.
Nonexperimental Methods of Psychological Research
As you first set out to learn about a phenomenon, you seek to observe it and describe it as it occurs. In this section, I will describe three of these nonexperimental research methods. They are the case study, naturalistic observation, and the correlational approach. Each of these has played an important role in the study of psychopathology.
Case Study
The case study is one of the most widely used methods for studying individual participants. It is based on the logic of describing, analyzing, interpreting, and evaluating a set of events and relationships within a framework or theory (Bromley, 1986). The typical descriptive case study focuses on either problematic or exceptional behaviors of one individual. Indeed, for years the case study approach has been the primary method for studying phenomena in clinical medicine, clinical psychology, and the neurosciences. It has a particularly important history in the study of mental disorders.
case study: a research method that typically focuses on recording the experiences and behaviors of one individual
The case study method has a rich tradition in studying unique situations that do not lend themselves to traditional experimental procedures. Much of our initial understanding of brain function came from careful study of individuals who had had accidents or experienced war injuries. With psychopathology, the case study offers a means of examining in some depth the manner in which a person understands and experiences his or her disorder. Further, the case study offers a means of helping researchers develop new questions to be asked concerning a disorder in terms of how it developed and might be treated.
In psychopathology research, the advantage of the case study is its ability to present the clinical implications of a particular disorder. One classic example that Freud discussed was the case study of Anna O., which I will introduce in Chapter 9. Another example is described in Morton Prince’s book The Dissociation of a Personality (1913). Prince described a case of multiple personality (now called dissociative identity disorder) at a time when the existence of that diagnostic category was in question.
An advantage of such extended discussions in a case study is the ability to describe processes not easily reduced to a single variable. For example, Luria (1972) described in great detail the attempt of one man to overcome a neuropsychological deficit that left him with “a shattered world.” This is a story about a brilliant young Russian scientist, Zasetsky, who became a soldier in World War II and was shot in the head. Zasetsky’s wound was such that areas of the brain that help one move in space or understand complex language were damaged, whereas areas that allow one to reflect on one’s condition were not. Luria’s intriguing work describes both his and the patient’s own experiences over a 25-year period. Initial case studies from battlefield experiences also helped to clarify the nature of post-traumatic stress disorder (PTSD), which will be discussed in Chapter 7.
Another famous case study in the history of neuropsychology is that of Phineas Gage. In 1848, Phineas Gage was a railroad construction supervisor in Vermont. Part of his job was to prepare the charges to blast rocks so that the railroad tracks could be laid. To do this, a hole would be drilled in the rock and then gunpowder would be placed in the hole followed by sand. This would then be tamped down with a long iron rod. On September 13, 1848, Gage did not realize that the sand had not been added and began to drop the iron rod into the hole. As the rod went into the rock, a spark ignited the gunpowder and the 13-pound iron rod shot out and through Gage’s brain, as shown in Figure 3.1, and landed some 30 feet away (Damasio, Grabowski, Frank, Galaburda, & Damasio, 1994).
Phineas Gage after the accident.
Public domain
Amazingly, after being momentarily stunned, Gage regained full consciousness and was able to talk and to walk with help. He was taken back to his boardinghouse and seen by a local doctor. What was surprising was that, over time, Phineas Gage was able to recover from his physical injuries. He continued to be able to speak and perform the everyday motor processes required. His intelligence and ability to learn new information remained as before the accident. However, his personality showed such a drastic change that his coworkers said he was “no longer Gage.” Whereas he had been a mild-mannered person before the accident, afterward he was prone to angry outbursts. Gage also lacked social conventions after the accident and frequently used profanity. The accident had influenced his emotional processing. This case study, as described by his physician, Dr. Harlow, has helped scientists understand the manner in which brain damage can influence social and emotional processes seen in other types of mental disorder. This helped later scientists consider which areas of the brain might
