Other way around, Mr. Fox. If what they say was true and they had larger brains, they'd probably be the elites of this world.
You cant say they were very good at communication though. You need something efficient to share your mind instead of grunts.
Scientists do have evidence of a language and they are already pretty complex in thought. But still, they'll be more of slaves and subject to bigotry due to their looks and brute force.
You also have to think of the weird inter-subspecies porn that they'll give us.
I'd also like to prove your claim. According to this wikipedia article, Neanderthals do have the anatomical qualifications for languages. Phooey, I thought we were special. Hmph, at least we don't look weird! Wait.
There is some circumstantial evidence for thinking that Neanderthals had language with words and some kind of syntax; some of their tool-making and hunting tactics would have been difficult to learn and execute without it. A recent extraction of DNA from Neanderthal bones indicates that Neanderthals had the same version of the FOXP2 gene as modern humans. This gene is known to play a role in human language.
The idea that Neanderthals lacked complex language was once widespread, despite concerns about the accuracy of reconstructions of the Neanderthal vocal tract, until 1983, when a Neanderthal hyoid bone was found at the Kebara Cave in Israel. The hyoid is a small bone that connects the musculature of the tongue and the larynx, and by bracing these structures against each other, allows a wider range of tongue and laryngeal movements than would otherwise have been possible. The presence of this bone implies that structured speech was anatomically possible and that the repertory of sounds that might be produced was wide enough to contain well-defined sets of phonemes, and not simply inarticulate guttural grunts. The bone found is virtually identical to that of modern humans.