No it strengthened social bonds, both toward family and friends and equally against others. It makes people VERY tribal.
Cortisol is also released in long term stressful situations. With a rising tide of poverty and climate blow back, I suspect stress will increase and so too will said tribalism.
What we see today with the rising popularist and isolationist political parties is but an echo of the future.
We see some of these tendencies when a few thousand or tens of thousands of refugees turn up in a country. What happens when this becomes millions? I have said it for years, many will be welcomed with open arms - those arms being machine guns, bombs and drones.
This is the dark future I fear and I hope I am wrong.
I do not have kids, it wasn't by choice. But what looked like something of a negative might actually turn out to be a near miss in future. Just keep your kids safe and try to have peace and compassion to others that are trying to do the same.