Biologists believe that chimpanzees share at least 98.4 percent of the same DNA as humans. Gorillas have a genetic composition which is at least 97 percent consistent with that of humans. Because the advancement of scientific technology has increasingly demonstrated similarities between animals and people, popular attitudes toward the use of animals in research and scientific experimentation have …
Behavior modification is based on the principles of operant conditioning, which were developed by American behaviorist B.F. Skinner (1904-1990). In his research, he put a rat in a cage later known as the Skinner Box, in which the rat could receive a food pellet by pressing on a bar. The food reward acted as a reinforcement by strengthening the rat's bar-pressing behavior. Skinner studied ho…
In simple psychological experiments, one characteristic—the independent variable—is manipulated by the experimenter to enable the study of its effects on another characteristic—the dependent variable. In many experiments, the independent variable is a characteristic that can either be present or absent. In these cases, one group of subjects represent the experiment group, wher…
Psychologists conduct experiments in order to isolate causes and effects. Ultimately, explaining human behavior consists of identifying the factors that have a causal influence on how we think or act. The most effective way to investigate causation is through experimentation. Different aspects of an experiment are best explained by providing an example. Suppose a researcher wants to find out if su…
One of the goals of 19th-century American scientists was to determine why some people engaged in undesirable or antisocial behavior. A family from Ulster County in upstate New York provided a great deal of material for speculation about the origins of such behavior. The family was referred to as the Jukes family (the actual family name was kept anonymous). One of the initial researchers of the Juk…
The history of intelligence testing in the United States has been troublesome from the beginning. Although psychologists attempted to conduct legitimate research and apply psychological knowledge to the study of intelligence, some of the early work was quite unscientific and led to dubious results. One case involved the descendants of an anonymous man referred to as Martin Kallikak. This man produ…
Stanley Milgram (1933-1984), an American experimental psychologist at Yale University, conducted a series of experiments on conformity and obedience to authority. In these experiments, Milgram recruited subjects—ordinary citizens—through newspaper advertisements offering four dollars for one hour's participation in a "study of memory." When the subject arrived at…
The Rosenzweig Picture Frustration test consists of 24 cartoon pictures, each portraying two persons in a frustrating situation. Each picture contains two "speech balloons," a filled one for the "frustrator" or antagonist, and a blank one for the frustrated person, or protagonist. The subject is asked to fill in the blank balloon with his or her response to the situatio…
Sensory deprivation experiments of the 1950s have shown that human beings need environmental stimulation to function normally. In a classic early experiment, college students lay on a cot in a small, empty cubicle nearly 24 hours a day, leaving only to eat and use the bathroom. They wore translucent goggles that let in light but prevented them from seeing any shapes or patterns, and they were fitt…