It asks how these models of human life course were developed, including what stages of development are defined, and what ‘proper’ paths each model of development dictates along these stages. Taking into consideration the social and economic environments in which these models were developed, it further evaluates how ‘outliers’ - i.e., individuals differing from the median of human development because of age, disability, physical, or mental capacity - have been incorporated into or excluded from these different models. Finally, it asks how different models may have influenced each other over the course the 20th century and what influence these models - and their interactions - have had on conceptions and programmes of social welfare.

• ageing
• disability