I have searched the internet, talkorigins, Baldwinian explanations,
and the post archive here and been unable to find a good explanation
of how instincts (not reflexes) originate.

My dad is reading the book "Improbable" by Adam Fawer, and apparently
it makes a case for a "shared consciousness" to explain instincts that
are not coded for in DNA. I have tried to explain the Baldwinian
effect to him but I cannot explain how exactly the DNA itself passes
instincts.

According to the book, Biologists have been unable to explain how
babies have the instinct (or skills) to walk, without ever seeing
walking in action.

I plan on reading "Improbable" to find out exactly what it says, but
can anyone explain how instincts are formed?

And can anyone explain why the concept of "shared consciousness" is
used in this regard? I havn't read the book yet, but apparently the
point is that some things that don't pass by DNA are instead contained
in everyone, in some meta-physical sense. I don't buy it, but maybe
someone with more education in meta-physics can explain it better.