What evidence is there to suggest that delayed gratification is taught and learned and not genetic?
whilst the nature-nurture issue in mammalian (and particularly human) behaviour is a perennially-fascinating topic, we have learned to be cautious about attempting to construct any strict dichotomies between learned and innate behaviour. suppose you had asked: "did I learn English or just have it?". 

successful delayed gratification most likely involves cognitively-mediated inhibition channeled via the frontal lobes. the behaviour must be learned, but it relies on a genetically encoded neural substrate. since it has been claimed (on the basis of longitudinal studies) that the degree of success in delayed gratification tasks persists over time, it may be interesting to ask a related question: if a person has a below-average ability to successfully delay gratification, to what extent is this due to poor teaching and to what extent is it based on neurological factors?