  Based on the universal properties of a critical point in different systems
and that the QCD phase transitions fall into the same universality classes as
the 3-dimensional Ising, $O(2)$ or $O(4)$ spin models, the critical behavior of
cumulants and higher cumulant ratios of the order parameter from the three
kinds of spin models is studied. We found that all higher cumulant ratios
change dramatically the sign near the critical temperature. The qualitative
critical behavior of the same order cumulant ratio is consistent in these three
models.
