In-group

There is a natural tendency for humans to define themselves in terms of in-groups and outsiders.

Creating a Universal In-Group

This makes sense from an evolutionary perspective, but in a globally connected society it can lead to chaos. There are so many overlapping in-groups that cross all national and cultural borders that attempting to define them in any way creates tons of exceptions.

The only morally defensible in-group when it comes to the utilitarian ethical calculus is all humans, and outside the realm of survival that should be expanded to also include all living things. Any hierarchical subdivision is inherently unjust.

Enforcement of Norms

Enforcement of cultural norms through taboos is only effective within one's in-group. A global culture with a universal in-group will enable humanity to share and enforce non-legally binding social norms that will be needed to prevent bad actors, such as spreaders of misinformation, from gaining influence on social media and other globally connected platforms.