Us is merely what we empathise with and understand, that which is similar to how we identify with ourselves. The “Other” or Them, is farther away on this spectrum.
We see that in a more primitive time, when societal groups were based on race and ethnicity, we would identify strongly as so, and also select for it.
The brain is very good at “short circuiting” stuff we already know, and engaging with the aberrant parts of incoming information, so the brain scans should merely speak to the familiarity of information and not directly of any underlying bias, even though both may have a common source (i.e. foreign information is the underlying cause, but these variables - brain scans and biases - are merely correlated).
In today’s age, we identify based on what we are now seeing as “higher” interests. The intelligent vs the stupid, the skilled vs the incompetent, etc. These are now forming the in and out groups in our collective minds. It must be said though that it would take a significant amount of information about, say, an individual African American skilled person to change them from merely a black person to a skilled person in a White man’s head because one can be inferred trivially by a picture and the other by more time and a deeper understanding. (Take with a pinch of salt :)
The point here is that we now understand that society’s interests are better served by selecting for traits that are, in a sense, more objective. Things like skill and intelligence and the ability to contribute positively to the world we live in. By encouraging this selection, we are creating an in-group to which an aspiration is a positive thing, positive here being the same as positive for society. It also means that people are less limited by their biological circumstances, which is an equalising platform.
Hard questions remain, such as access to education and information that influences the position of a person with respect to the in-group. But I would argue that this is at least a positive evolution from where we have been.
Something also should be said about the ability to take every individual and every circumstance as unique, and be able to help each attain the maximum potential as per your own selected ideals, but this would require a radical individuality and awareness of self, and an extreme ability to understand and communicate with every other person. In this world, there would be no groups. But we’re probably not quite close to this world yet.