Holy shit that dog looks vicious. But, back to the comparative anthropology between homo sapiens and neanderthals. I love this topic...
Here's a short wikipedia article on what it means for a human to be "modern" and the two competing theories as to why/when that happened.
http://en.wikipedia.org/wiki/Behavioral_modernity
I ascribe more to the "Great Leap Forward" idea - that "modern" homo sapiens emerged quite suddenly from our more archaic forebears.
There's lots of theories as to why/how this happened 50,000 yrs ago. And who knows? It was probably a synergistic effect from co-occuring factors. The "theory of the mind" concept is the part I like best. Somehow (genetic mutation, advent of cooking which released more nutrients to fuel more brain power, etc?) our brain developed the capacity for complex speech - likely during cooperative hunting. This allowed the emergence of a proper mind (it's harder to think to yourself w/out complex language). Homo sapiens became aware of the concept of self, developed an ID, an ego, and basically considered their consciousness and what was up w/, well, everything. The universe, nature, and all those questions we still wonder about today as humans. This then, almost immediately, spurred an explosion of culture to fully express this new consciousness.
Meanwhile, with more advancement, humans have more TIME to sit around, discuss, and THINK about all this stuff. Not everyone had to hunt/gather 24/7. This then leads to some people having the time, purposefully afforded by the group/tribe, to specialize and LEARN new things. The first was the Shaman.