The origins of both Neanderthals and Homosapiens etc. are still very much the subject of debate, as are disagreements about what attributes should be considered typical for either or both. A growing consensus attributes much higher intelligence to Neanderthals than was assumed by earlier researchers, but it's not unlikely they were "differently intelligent" than other more or less successful groups.

One recent proposition that's received very little debate is from evidence that Neanderthals were predominately "red haired" so the carrot-top trait may have come from them. (Little comment has appeared on whether they were fair-skinned - under all that hair they they might have had - and had freckles like many modern red-heads.) It's unclear whether the sparse debate is because other researchers don't think there's enough evidence to reach a conclusion or whether they just don't think it's interesting enough to justify debate.

It's what we don't know that's most interesting, but it's what we don't know we don't know (the "UNK UNKs") that make it difficult characterize our multiple genetic ancestors with a lot of confidence.

John