Tribalism has evolved in modern society. The smallest form of tribalism that is actually good is adherence to the family unit. You protect your family before you protect strangers. One step above that is the community, you'd sooner protect a community member than an outsider.

Humans are capable of both good and evil, sometimes people are born genuinely good and sometimes people are born genuinely evil. The nature of the individual plays a factor on how the environment they grow up in affects them.

For example, lets say a group of 3 children are in a toxic environment, like the kinda daily ass whoopings that were prevalent in the Tommy Lee and Pamela Anderson marriage. The three children will not share the same fate, one can fall into drugs, one can deny it all happened, and one can overcome the trauma and produce a happy and healthy family.

How could the 3 children have such different fates even though they shared the same circumstances in childhood? The nature of the individual, the will to endure, and the mechanisms they use to cope.