do moral anti realists act any different than realists?

Because just about everyone has a sort of innate evolutionary moral compass, it would seem that an anti realist would act in just about the same way as a realist, even if they intellectualized moral acts to not really have any value. Also, is it common for anti realists to follow normative moral systems? Like an anti realist utilitarian who subjectively thinks suffering is bad and acts like a utilitarian but concedes that suffering is not objectively bad?