Final answer:
Parsons argued that the nuclear family was optimal in industrialized societies because they were more adaptable and it suited the urban lifestyle better, along with the economic demand for a smaller, more mobile family unit.
Step-by-step explanation:
Talcott Parsons argued that the nuclear family was better suited for industrialized societies due to the changing economic and social demands. In a pre-industrial society, extended families played a crucial role in production and support, which the smaller nuclear family couldn't match. However, as industrialization progressed, large families were no longer necessary for manual labor on farms, and job opportunities tended to concentrate near urban centers where living space was limited. This economic shift favored the nuclear family, which was more mobile and better adapted to urban living conditions. Moreover, the decline of marriage and the rise of new familial structures reflect ongoing changes in societal norms and economic requirements.