There is really very little separating nature and nurture.
An example from gibbon research - gibbons are the textbook example of monogamy amongst primates. They mate for life, eat a high quality diet (fruit and insects with some leaves and other greens). The pair sing together in the mornings and evenings to proclaim there territories. The female takes care of infants until they are weaned and then the male takes over rearing offspring. Before the infant is weaned they are the color of the mother then when their father takes over they become the color of their father. At puberty males stay black like their father and the females become golden like their mothers. Within the family females tend to be dominant and males tend to defend the family against outsiders but they aren't strongly hierarchical.
That said there is a group of gibbons that no longer have the same high quality diet their diet is primarily leaves and greens. Their social structure is one or two dominant males with a group of subordinate females. Thus their social structure resembles that of baboons rather than other gibbons.
So, does high quality diet lead to sexual equality and pacifism or are these just anecdotes?
Sorry I was unclear and yes, I indulged myself on the development because I think it is so neat.
To clarify the conclusion I am proposing that diet may be the key to social structure in both the baboon and gibbon case – high quality food -> non-hierarchical and pacifist – low quality food -> hierarchical and aggressive.
Since diet part of the experience of the animal is it nature or nurture or something in else? Does the diet trigger a genetic reaction or is it that with secure access to high quality food there is no reason for hierarchy and aggression?
And yes, it should be, “The pair sing together in the mornings and evenings to proclaim THEIR territories” not "there territories". Thank you.