From the best biology we know: the acquisition of traits (phenotype) is both a product of nature (genotype) and nurture. Is it racist to say that we should not expect a cat to do calculus? Is it racist to say a mouse may never be able to write a book? These are rhetorical questions, but as a bottom line I would say it is good to not expect complete uniformity of ability in all of Hashem’s created beings, which of course does not dictate license for bigotry.
G-d does not harbor excess in His creation. When something exists, it is supposed to be that way because Hashem has ordained for it to be as such. Thus, it is such that while I won’t deny anyone, even a different species of animal or a computer (maybe someday), proper education if aptitude is demonstrated, there does come a time when we should realize that it is cruel to hold onto expectations that the problem of dumbness be alleviated merely by endless hard work. Rather, we should give credit and encouragement where it is due.
Should we expect a human to run as fast as a cheetah? Should we expect humans to regularly give birth to as many offspring as mice? Some of our greatest strengths may be in our inherent differences because created species, nations, and beings are not meant to be completely alike.