(Background of current psychology) Stimulus-response experiments are sufficient for experiments on lower psychological functions.

Qualitative distinction between animal and human behaviour. (p.60) (Note: historical distinction - may be objectionable to some parts of ecology movement. Counterpoint Tepper: some humans behave like animals and some animals behave like humans.)

Engels: approaches to understanding human history. (p.60)

• Naturalistic approach: "only nature affects human beings and only natural conditions determine historical development."
• Dialectical approach: "while admiting the influence of nature on man, asserts that man, in turn, affects nature and creates through his changes in nature new natural conditions for his existence."

Stimulus-response methods in psychology are similar to naturalistic approaches in history. "Both see the relation between human behaviour and nature as unidirectionally reactive." (p.61)

Alternative methods are necessary for higher psychological functions. Vygotsky highlights three principles:

• Analyzing processes, not objects. Psychological processes cannot be considered as fixed objects, as they are undergoing change. It is therefore important to trace the historical development of the process. ("To study something historically means to study it in the process of change", pp.64-65)
• Explanative vs. descriptive. By analogy with biological distinction between phenotype and genotype, Lewin contrasts the external features of a phenomenon with the internal processes that give rise to the phenomenon. Two phenomena may have the same external appearance but have different internal causes (and vice versa). "Thus, psychologoical analysis in our sense rejects nominal descriptions and seeks instead to determine causal-dynamic relations. However, such explanation would also be impossible if we ignored the external manifestations of things. By necessity, objective analysisincludes a scientific explanation of both external manifestations and the process under study". (p.63)
• Problem of "fossilized behaviour". "...processes that have gone through a very long stage of historical development and have become fossilized." (p.63) It is necessary to reconstruct the processes in the development of a particular psychological function.

Example: psychology of complex choice responses.

Usual theory considers that the response time in these experiments is equal to the arithmetic sum of the time of the simple reaction plus the discrimination plus the choice. Instead experiments show that times for complex choice and simple reaction experiments can be equal. One problem is the subjects need to learn the experiment. Early trials, (in which the learning process may be evident) are discarded in order of find an average response time for the activity.

Causal-dynamic method.

Vygotsky's conclusions.