This whole discussion is rendererd meaningless by the underlying assumption that there is something called "intelligence" that can be quantified by some measure (brain size, brain weight, IQ test score, etc.). This is what Steven J Gould referred to as the fallacy of reification in his classic book The Mismeasure of Man. I'd recommend that anyone jumping into a discussion like this read it if they haven't already.

Yes, some people are more "intelligent" than others, but making efforts to shoehorn this very complex phenomenom into a single number and assume that that number means anything is futile. It is, as Lord Kelvin would say, "Knowledge of a meagre and unsatisfactory kind."

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"I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind." - William Thompson, 1st Baron Lord Kelvin

"If it was so, it might be, and if it were so, it would be, but as it isn't, it ain't. That's logic!" - Tweedledee

This isn't right. This isn't even wrong. - Wolfgang Pauli