Final answer:
The formation of social diversity since the 1960s has been influenced by evolving family definitions and societal attitudes towards family units. These changes include accepting single-parent households, cohabitating unmarried couples, and diverse child-rearing roles, while rigid employment practices have not contributed to this diversity.
Step-by-step explanation:
Since the 1960s, a variety of factors have contributed to the formation of social diversity, with many relating to changing family structures and societal attitudes. One key factor is the evolution in the definition of what constitutes a family unit, moving away from traditional nuclear families to include a broader spectrum such as single-parent households, cohabitating unmarried couples, and same-sex partnerships. Additionally, the shift in roles regarding child-rearing, where both fathers and mothers may share responsibilities more equally, has also influenced this diversity. Economic factors, such as the need for dual-income households, and cultural factors, including increased acceptance of diverse family forms, have also played a significant role.
However, one factor that has not contributed to family diversity since the 1960s would presumably be something that doesn't fit with the progressive changes observed during this period. Possible examples include rigid employment hiring and salary decisions based on gender roles, which have been more about maintaining the status quo rather than contributing to diversity in family structures.