It has nothing to do with their body, but everything to do with their mind. Impulse-control with planning ahead is sometimes not one of their strong suits. They score lower on the marshmallow test than cuttlefish according to a referenced study here. When brain oxygen levels drop below a certain level the lizard brain kicks in and says "gibs me now!" and then they go into fight/flight mode which only makes it worse. When they don't know what to do they go into spaz mode because more energy always solves problems. Many are just not genetically capable of the mirror test either and recognizing when the outcome is inverse to the effort. Look at the hysterical cases of death and/or reactive murders when they can't get their way immediately..