Final answer:
The statement is false because cultural universals exist, suggesting an interplay between nature and nurture in the development of cultures. Anthropologist Franz Boas emphasized that cultural development involves interaction, countering the idea that cultures are exclusively products of nurture.
Step-by-step explanation:
The statement that the repeated finding by sociologists and anthropologists that there are no 'cultural universals' is conclusive proof that cultures are the product of nurture rather than nature is false. While it's true that cultural universals, such as the family unit, funeral rites, weddings, and celebrations of births, exist across societies globally, the ways in which they are expressed and enacted can differ significantly due to nurture, or the cultural environment. However, the presence of such universals suggests an interplay between nature and nurture, implying that certain aspects of culture may also be rooted in our biological predispositions. Anthropologists like Franz Boas emphasized that cultures develop through interactions and are not isolated, which reveals the nuanced relationship between the inherent human capacities and the diverse cultural expressions shaped by environmental and historical conditions.