Theories: Specifying Broad Explanations
In using the scientific method, psychologists start by identifying questions of interest. We have all been curious at some time about our observations of everyday behavior. If you have ever asked yourself why a particular teacher is so easily annoyed, why a friend is always late for appointments, or how your dog understands your commands, you have been formulating questions about behavior.
Psychologists, too, ask questions about the nature and causes of behavior. They may wish to explore explanations for everyday behaviors or for various phenomena. They may also pose questions that build on findings from their previous research or from research carried out by other psychologists. Or they may produce new questions that are based on curiosity, creativity, or insight. Once a question has been identified, the next step in the scientific method is to develop a theory to explain the observed phenomenon. Theories are broad explanations and predictions concerning phenomena of interest. They provide a framework for understanding the relationships among a set of otherwise unorganized facts or principles.
All of us have developed our own informal theories of human behavior, such as “People are basically good” or “People’s behavior is usually motivated by self-interest.” However, psychologists’ theories are more formal and focused. They are established on the basis of a careful study of the psychological literature to identify earlier relevant research and previously formulated theories, as well as psychologists’ general
knowledge of the field. Growing out of the diverse approaches employed by psychologists, theories
vary both in their breadth and in their level of detail. For example, one theory might seek to explain and predict a phenomenon as broad as emotional experience. A narrower theory might attempt to explain why people display the emotion of fear nonverbally after receiving a threat (Guerrero, La Valley, & Farinelli, 2008; Waller, Cray, & Burrows, 2008). Psychologists Bibb Latané and John Darley, responding to the failure of bystanders to intervene when Kitty Genovese was murdered in New York, developed what they called a theory of diffusion of responsibility (Latané & Darley, 1970). According to their theory, the greater the number of bystanders or witnesses to an event that calls for helping behavior, the more the responsibility for helping is perceived to be shared by all the bystanders. Thus, the greater the number of bystanders in an emergency situation, the smaller the share of the responsibility each person feels—and the less likely that any single person will come forward to help.
Hypotheses: Crafting Testable Predictions
Although the diffusion of responsibility theory seems to make sense, it represented only the beginning phase of Latané and Darley’s investigative process. Their next step was to devise a way to test their theory. To do this, they needed to create a hypothesis. A hypothesis is a prediction stated in a way that allows it
to be tested. Hypotheses stem from theories; they help test the underlying soundness of theories.
In the same way that we develop our own broad theories about the world, we also construct hypotheses about events and behavior. Those hypotheses can range from trivialities (such as why our English instructor wears those weird shirts) to more meaningful matters (such as what is the best way to study for a test). Although we rarely test these hypotheses systematically, we do try to determine whether they are right.
Perhaps we try comparing two strategies: cramming the night before an exam versus spreading out our study over several nights. By assessing which approach yields better test performance, we have created a way to compare the two strategies.
A hypothesis must be restated in a way that will allow it to be tested, which involves creating an operational definition. An operational definition is the translation of a hypothesis into specific, testable procedures that can be measured and observed.
There is no single way to go about devising an operational definition for a hypothesis; it depends on logic, the equipment and facilities available, the psychological perspective being employed, and ultimately the creativity of the researcher. For example, one researcher might develop a hypothesis that uses as an operational definition of “fear” an increase in heart rate. In contrast, another psychologist might
use as an operational definition of “fear” a written response to the question “How much fear are you experiencing at this moment?”
Latané and Darley’s hypothesis was a straightforward prediction from their more general theory of diffusion of responsibility: The more people who witness an emergency situation, the less likely it is that help will be given to a victim. They could, of course, have chosen another hypothesis (try to think of one!), but their initial
formulation seemed to offer the most direct test of the theory.
Psychologists rely on formal theories and hypotheses for many reasons. For one thing, theories and hypotheses allow them to make sense of unorganized, separate observations and bits of information by permitting them to place the pieces within a coherent framework. In addition, theories and hypotheses offer psychologists the opportunity to move beyond known facts and make deductions about unexplained
phenomena and develop ideas for future investigation (Cohen, 2003; Gurin, 2006; Howitt & Cramer, 2000).
In short, the scientific method, with its emphasis on theories and hypotheses, helps psychologists pose appropriate questions. With properly stated questions in hand, psychologists then can choose from a variety of research methods to find answers..
