Raymond,

"The only way we can compare the experience of one person with another is by comparing their behavior. This includes both their verbal behavior and their non-verbal behavior. "

Something needs to happen before that. Our experience is given first, and this experience identifies the physical events that we call behaviour. Without the identifying or transcendental condition of experience then there are no behaviours, only physical movements, and these indistinguishable from one another simply because they have no conditions for being picked out.

Once we associate a physical event or movement with an experience then we rename that physical movement a behaviour. Once that assocation is made then we can also leap to the assertion that similar physical events point to an experience - provided, of course, that we don't lose sight of the fact that the original physical event is picked out by an experience (something the neuroscientists always forget) and not vice versa.