This is a stupid question (good that I ask). String theory treats bosons and fermions in different ways e.g fermion potential are differ from boson potentials,actions differ and so on... My question is simply : why? Yes I know fermions and bosons are different groups of particles (integer and non-integer spin) and have many differences, but how are these incoperated in the action or potential. Specifically why does one need anticomuting dynamical variables for fermions? Thanks for any clarifications.