In this paper, we investigated the relation between gamma nonproportionality and alpha particle nonproportionality. First, we collected literature data on the α/β ratio of almost all commonly used scintillators. Second, we extended the literature review with our own measurements of LaBr3:Ce α/β ratio in function of Ce3+ concentration. A strong influence of codoping on the α/β ratio of LaBr3:Ce has been observed. Finally, we conclude that the gamma nonproportionality, gamma intrinsic energy resolution, and α particle response are closely related to each other, and they are due to quenching in the high density part of ionization tracks. Though it still needs to be tested for a larger group of scintillators, α/β can be used as a single value characterizing intensity of light quenching processes in scintillators.