Young-earth creationists rightly consider that Neanderthals were human, but are divided on various issues, mainly because of the opposing views of Jack Cuozzo, author of Buried Alive! and Marvin Lubenow, author of Bones of Contention. These differences include Neanderthal lifespan, causes of the Neanderthal distinctive morphology, why the Neanderthals disappeared, length of Neanderthal children's maturation time, whether we can place Neanderthals in biblical history, and the related issue of whether Homo erectus was human. In addition, Neanderthals are implicated in matters that include the Babel dispersion, earth's breakup, DNA, patterns of world population, the Ice Age, archaeology, and historical timeline.
http://www.answersingenesis.org/articles/arj/v3/n1/neanderthals