One interesting thing in quantum mechanics is that there are correlation effects which can manifest themselves as dynamic effects, for example, as kinematics of fermions can make free electron model a good approximation for some phenomenons observed in solids, by effective cancellation of very strong Coulomb interactions. Now, could it be possible that there is some other quantum number besides spin, which is connected with kinematics, namely mass, which creates strong correlation for large systems? I asked myself this question when I wondered why mass has dual role. It acts both as inertial parameter, both as a quantum number determining how gravitation couples to a particle. It's inertial role stems from Poincare group while dynamical role is currently based on phenomenology. On the other side, spin also gets its inertial role from Poincare group, but we have spin-statistics theorem connecting it to kinematics which is in term responsible for appearance of what are effectively dynamical effects throughout nature. In a way, gravitation as kinematic correlation would put mass and spin, as two quantum numbers stemming from symmetry, on equal footing. Now since I am a noob (busy one currently) I don't have enough knowledge to put some serious thought into this so I would like to here some thoughts from pros on this (and hopefully learn something), for example, are there any principles that tell us that gravity must be interaction in classic sense, ie. being transmitted by particle, corresponding to gauge potential etc.