Future Success and Delayed Gratification

Here is interesting experiment ,( And funny too ) - which evaluates delayed gratification and links it with future success. I find it interesting . I wonder whether the traditional Indian wisdom of asking children to wait for everything has links with success ?

More-over - it does mean that self-discipline is really important in all walks of life .

Still experiment raises one question in mind - whether ( in general ) 1/3rd population has more potential for success ?