I agree we are tribal and it isn't always bad

we are genetically tribal right from the start of humanity. see the genome project by national geographic

From an anthropological aspect of speaking I think there is much merit to what she said. We have survived as a species due to tribalism and working together to survive. This in itself may be correct, but in the context that she is thinking of it is very wrong.

Let's say that this is KKK.com. The ideas we would share would be harmful and very limited to a specific type of thinking.
Now let's say it was humanism.com now we have taken our "tribalism" in a much broader and useful direction. Our humanistic beliefs may lead us to coordinate humanitarian aid for earthquake victims, or work for human rights in a specific region of the world. In this case even with focused attention we have made very good use of "tribalism".

I have believed that atheist wet the most diverse group on the planet as atheist only share one idea, that being that God does not exist. This group is even more diverse. I am a staunch or "hard" atheist. There are some that are self proclaimed theist. This group is in fact a group so by definition we do fit into the category of tribalism. From a sociological point of view it is impossible for any group to get together and not be a part of the sociological psyche of tribalism. If you are stuck in an international airport due to being snowed in than the common ground and "group think" will be to get to a certain destination wether people actually can communicate in the same language or not.
So tribalism in itself is not bad at all. She has limited her mind to the adverse aspects of tribalism that includes such aspects as actually limiting thought as often happens is things like say.....religion.

It seems obvious to me that we are evolved for tribal life, rather than "civilized" life. We gather round each other based on ideology and often cannot even stand to hear another side.

In a youtube interview with David Letterman, President Obama talked about how we are living in "bubbles" where we only select media online that matches our current bias, and that the current system of media really leads us to these bubbles.

I don't think it's a new problem, but it is one nonetheless.

I think that it is fine to block people who attack our beliefs with rudeness and name calling. But I would caution blocking different views simply because they make us uncomfortable.

I am not seeking positive reinforcement, and from what I have read the same applies to at least 50% of the contributors here. I made my own mind up in a void, didn't need others who thought he same, I would continue with my own thoughts regardless. I am here like leech, to get other peoples insights on a whole range of issues.