蘇大英語閱讀理解-1

What does a scientist do when he or she"explains something? Scientific explanation comes in two forms:generalization and reduction. Most psychologists deal with generalization. Theyexplain parlicular instances of behavior as example of general laws. Forinstance, most psychologists would explain a pathologically (病態) strong fear of dogs as example of classicalconditioning. Presumably, the person was frightened earlier in life by a dog.An unpleasant stimulus was paired with the sight of the animal (perhaps theperson was knocked down by a vigorous dog and the subsequent sight of dogsevokes the earlier response of fear.

Most physiologists deal with reduction.Phenomena are explained in terms of simpler phenomena. For examjle, themovement of a muscle is explained in terms of changes in the membrane (生物膜)of muscle cells, entry of particular chemicalsand interactions between protein molecules within these cells. A molecularbiologist would "explain" these events in terms of forces that bindvarious molecules together and cause various parts of these molecules to beattracted to one another.

The task of physiological psychology is to"explain" behavior in physiological terms. Like other scientists,physiological psychologists believe that all natural phenomena-- includinghuman behavior--are subject to the laws of physics. Thus, the law of behaviorcan be reduced to description of physiological processes.