>>14126840The more you know about a group of people, the more you know about the variability within that group. This is because the very act of grouping is to remove all extraneous information and to concentrate on that which is common. For example, if you were to say to an alien lifeform with no knowledge of humans, that humans can be divided into "white people" and "coloured people", the only thing the alien will now about a human who is white is that they are white (by definition). If you were then to say the group of "white people" can be split into those men and women, then he knows that now there exists more heterogeneity within "white people" insofar as they can be split into "men" and "women". This process can continue until the limiting trivial subgrouping of "white people" is such that every single person is in their own group and only their own group. The sequence of subsetting "white people" until we get to the trivial grouping of every single person in their own group entails acquisition of knowledge of everyone. Therefore, it is clear that the more you know about a group, the more you know about the existent variability, the less you know, the less you about the variability.
It is plausible that one knows more about one's own ingroup than out-groups. It is also plausible that one assumes as much as they know. Therefore, one assumes there is less variability (more similarity) among outgroups than ingroups.
