http://esciencenews.com/articles/201...s.can.be.tamed
TL;DR - Tolerating humans in dogs vs. wolves differs due to timing of their socialization gene during the critical 1st month. The gene for wolves to accept humans asserts at 2 weeks old, but for dogs it asserts at 4 weeks old. That's before wolves can see or hear. But the human acceptance window is still open when dogs begin to see & hear. So it's important to socialize very early.