We only have differences in degree (of features) with chimpanzees, there are no unambiguous differences of kind. We differ just quantitatively, not qualitatively.
The genetic distance between us and chimps is very small (small enough that interbreeding might be possible). Then why the vast differences in form and behavior? Genes do not just determine traits. During development, different genes must turn on and off with exquisite timing to achieve differences from the same genetic system. For example, when a hand forms from a homogeneous limb bud, cells must proliferate in some areas (destined to be fingers) and die in others (the spaces between them).
We have genetic differences most likely in regulatory genes, that control this timing, resulting in large differences with only a few (relatively) differing genes.
Ever Since Darwin: Reflections in Natural History by Stephen Jay Gould
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