A bit is the fundamental unit of information theory, and has nothing to do with digital logic in this context. No one is saying "ok use one bit to encode male or female". No one is saying "ok 101 means serotonin, and 110 is dopamine". What they are saying is that the information content produced by a human being can be compressed down to about 10 bits per second, but this is a statistical description.
"Compression" here is nontechnical, and I was using it by analogy as an aid to intuition. I didn't want to throw out the E word (entropy) unnecessarily.
