Eating people is wrong

IN this book, Emma fielding realises that everyone must take up some space in the world, so some harm is inevitable. i.e. there is a cost of living.

The people bearing the brunt of this are at the edges of society, and it is at the edges where our true nature is revealed. In the animal kingdom, the runts take the brunt, and since we are also animals why not apply the term to humans?

A runt is someone whom the tribe/society has "decided" takes up too much space (too much meaning they are a threat to the survival of the tribe/society). Relinquishing this space then becomes a matter of life or death (in the wild, an abandoned runt will die). The solution for the runt is either to accept this smaller space and adapt within it (the source of all innovation) or to flee to a place that has more space (fighting is assumed not an option since by definition the runt would lose). Human runts are those who have fled from their 'hometown' to seek better prospects.

How does this bear out to statistics? What are the statistics of depression and divorce in the western world amongst people of native parents vs mixed parents or displaced people?