then Ridley's theory is impossible
A) We're most certainly not born with a blank sheet; if we were we couldn't breathe.
2) I haven't read the Ridley, but I think this is Pinker's theory we're discussing here (or someone else started it {Sapir? Whorf? No, Chomsky. That's who started it.}), Ridley merely discusses it, so let's not be trashing Ridley for our misunderstanding when it's really Pinker and/or Chomsky we should be trashing.
Þ) I have read about this theory in Pinker's The Language Instinct and, while I can't claim to understand it fully, I believe that they are talking about hard-wired syntax and grammar at a deeper level than that we poor mortals normally associate with those concepts.
Side issue:
Lactose intolerance was the norm before we started raising dairy cattle. The idea that anyone over the age of about 3 or 4 would be ingesting any lactose at all, much less the lactose from animals other than man, was unthinkable. It still is in some cultures. The Japanese, e.g., consider the idea of eating cheese somewhat revolting. The present day resurgence of lactose intolerance is, I think, more akin to a general rise of food allergies such as the famous peanut intolerance and is due to other factors. Dr. Bill and I have discussed this in PM and he has offered some interesting ideas on the subject, ideas which, I fear, I do not remember well enough to reiterate here.
