In my opinion no one culture really stood out as supreme each family was given the tools to raise a child in their society. It's hard to say that the modern style was better than the rural or vice-versa because from what was shown all the babies basically reached the same goal. They all, by the end of the movie, had learned to crawl around and explore their world. So not one style allowed the babies to accomplish something that others would not.
However there were some advantages the style used by the Japanese and American parents. Their babies were taken to a play group with other babies and learned to play and interact with others, making them more social. This is something that didn't happen as much in Namibia and hardly at all in Mongolia. The baby in Japan spent much more time with other babies and would probably gain more social skills that would help her later in life.
What looked universal - common to all humans - from the film - at least as edited? Why is this universality significant?
What looked universal to all the parenting styles was the fact that all the parents got help, at least somewhat. In both Japan and San Fransisco the babies went to play groups but also spent time with grandparents, who helped the parents raise the babies. Additionally in San Fransisco the Mother was seen reading a book about being a good parent and raising the kid well. In Nambia the mother got assistance from not only the other mother but from the other children, the baby was often seen around other kids who help raise him and make him who he is. This is important to note and to realize because from it we can learn that raising baby is done by a group of people not just the mom and dad or just the mom. It further proves the idea that it takes a village to raise a child not just the parents.
Another commonality between the babies was that for the most part they were raised by their mothers more than anyone else. The baby in Japan spent most of her time with her mother, the mom was the one that took her to all of her play groups and was seen in nearly every scene with her, much more than the father. In Namibia there was no father what so ever there was the mother, another woman and the brothers. The mother was again seen as the most important person in the baby's life. In Mongolia we saw a father but he was rarely taking care of the baby, instead he was just riding his motorcycle and working outside, the mother was much more involved with the baby. Although the father was more involved in San Fransisco the baby still spent most of her time with her mother. She was her main caregiver and seemed closer to the mother.
