History has shown that prevailing scientific views and social forces entwine to form a socio-historical line that becomes the culture that shapes and uses tools. The tools may be psychological ones acting internally, or technical ones that act on the environment.(Millar,1993:388) .
Vygotsky and Piaget were contemporaries with Watson and Skinner (behaviourists), Freud, (psychoanalysis) and Koffka (Gestalt psychology). (Bodrova & Leong, 1996:7) During the early part of the 20th century, the emerging field of psychology was linked to Darwinism and biological causes for behaviour. Eugenics (deliberate breeding of "superior" humans) was actively promoted in many Western countries. It was thought that behavioural and physical characteristics could be bred into, and out of, populations. .
Piaget's theory reflects his training in biology and philosophy. The main questions to be answered by a biologist are, what enables an organism to adapt to its environment, and what is the most useful way to classify organisms.(Lefrancois, 1999:46).
Vygotsky was a Russian-Jew at the time of the Communist revolution. He died from tuberculosis in 1938. He was strongly influenced by behaviourism.
His theory reflects the influence of Marx and Engels. Although he had constraints placed on his work by political forces, and was eventually blacklisted, students were able to retain his research and made it available during the 1950's. (Bodrova & Leong, 1996:184-185).
These two theories challenged behaviourism by allowing the possibility that people direct their own behaviour, either from internal drive (Piaget) or by shaping others mental processes (Vygotsky).
Each theory has some elements that have been incorporated into the lifespan development perspective. The first of the four assumptions of lifespan development that I will consider is that development continues for the entire life. Secondly that it occurs in multiple contexts.