Given that I have no experience of being deaf or blind, and have not looked into it very much, my intuitions on this point are not very well-informed; so I wanted to explicitly flag it as quite speculative.
It also happened at an early age. From a perspective that revolves around information this is a disadvantage. From a human perspective, losing a capability later seems like it can be more devastating. This suggests:
My explanation for this: the learning problem Helen faced was much harder than what most of us face, but because her brain architecture had already been “trained” by evolution, she could make use of those implicit priors to match, and then surpass, most of her contemporaries.
that “training” (learning) happened prior to Harvard but while alive. (“Evolution can “design” but not train,” and the formulation in terms of priors seems clunky.)
(Doesn’t touch on main points a lot.)
It also happened at an early age. From a perspective that revolves around information this is a disadvantage. From a human perspective, losing a capability later seems like it can be more devastating. This suggests:
that “training” (learning) happened prior to Harvard but while alive. (“Evolution can “design” but not train,” and the formulation in terms of priors seems clunky.)