The nasty neighbor effect in humans

I take psych research with a grain of salt after witness people such as Dan Ariely. It's very easy to be like "oh this is 'soft' research" and create a bit of a study that is 90% interesting hypothesis and 10% evidence. They're all "Twilight Zone" style hypothesii where there's an ironic twist at the end. Such as drug dealers are the same as sumo wrestlers or presidents operate like toddlers, or whatever interesting irony or generalization strikes the public fancy for novelty. In this context, the term "nasty neighbors" feels like a marketing-hype type term.

Within a country people still compete against each other which is an in group. It’s very arbitrary how we define in group and out group. We create one when we see fit, even brothers can compete with each other

I have no idea what this abstract is saying. It's like word soup. Maybe it's too late at night to read this.