Snapedom

But, over the years, many people have argued that being smarter does make you better, and that some races or groups are smarter and better than others.

An important thing to remember is that even if two groups differ by average ability in any particular measure, most of the time this does not apply to all individuals of said groups, because the distributions overlap. So even if group A on average produces better marathon runners than group B and group C on average produces musicians with better absolute hearing than group D (or whatever) knowing which group a randomly picked person comes from says nothing about that individual. If you want the most suitable person for a task you need to look at each individual's abilities and can't use group membership as a substitute for that (though it won't be surprising if your set of top candidates will have over-representation of whichever group in the population that averages higher in whichever talent that is relevant).