I agree with others that this sounds a bit like a slippery slope fallacy. However, thought of a bit differently, that practicing on the smaller things helps you

I agree with others that this sounds a bit like a slippery slope fallacy. However, thought of a bit differently, that practicing on the smaller things helps you on the larger, makes more sense to me. That said, I'm not sure if there's data to support that. Does being meticulous in your speech and not telling white lies make you less likely to cheat on your wife, say?