Can 4 year olds be temperate in the presence of a marshmallow?

Martin Seligman describes temperance as including,

…the ability to protect against excess and delay gratification. It includes humility and modesty. And being careful about choices and not taking undue risks. It also includes forgiveness and giving people a second chance. There is an aspect of self-regulation here – controlling your appetite and emotions, being disciplined, regulating what you feel and do. The temperate person does not suppress motives or desires but waits for until it is wise and appropriate to satisfy them, so no harm is done to self or others. read more