If we're being strictly anthropological Western 'racism' is a type of caste system but all caste systems have the trait of assigning better or worse outcomes to disparate breeding pools, however defined, and re-enforcing breeding rights on some level. Almost all human societies are caste systems of some sort since the introduction of farming at least, and from a more modern perspective is a composite of multiple, simultaneous caste systems (usually referred derisively as 'isms').
