Humans are tribal in hundreds of different dimensions. For example, If two people riding Harley motorcycles and two other people driving converted camper vans

Humans are tribal in hundreds of different dimensions. For example, If two people riding Harley motorcycles and two other people driving converted camper vans all arrive at a rest stop at the same time, it is likely that they will be friendly with each other based on the type of vehicle they arrived in. But religion,politics,race,gender,age,nationality all can be big ones as well. Syria hits a lot of those.