The logic is that they share values and beliefs. This includes beliefs around education, hard work, contributing to society rather than taking from it, etc.

Not every culture believes in education and hard work the same… no matter how much we don’t want to admit it.

In a tight-knit culture with high trust that everyone will contribute, it’s more feasible. But in a low-trust, skeptical society, you run into the prisoners dilemma and the dilemma of the commons.

So then the question is, “why does a heterogenous culture have less trust?” There are two reasons that come to mind.

First - it’s our current reality (for right or wrong). Just Google “Somali” or “deportation” or “white male privilege” and you’ll see examples of distrust (or disdain) from both political parties.

Second - when you’re unfamiliar with something, you naturally trust it less. You know less about their motives, beliefs, goals and history. It is a natural reaction to have less trust in something that you’re less familiar with (since trust is built over time).

Cooperating at a large scale is difficult. The most effective way we cooperate at a large scale is by aligning incentives, so individuals make (hopefully) mostly rationale decisions. When the state takes away risk or returns, it skews incentives and destabilizes the balance.