I do wonder about the effect on the attention span of the developing brain. Frustration is a feeling state that emanates from our innate aggression. If it cannot be tolerated, aggression in words or in deeds is the result. The child learns to do without some things, and to be patient and wait for others. Primary narcissism is tamed.
Tolerance requires the development of empathy.
And empathy requires time to think about another person while putting aside one's own needs or wishes. Children's early use of the new technologies is causing a profound change in how they experience the passage of time, and they are less willing to wait for what they perceive as long periods of time. I am impressed by the apparent link between technology, instant gratification, poor frustration tolerance, lack of empathy and aggression. As with all technological advances, these are unintended consequences which should raise some concern, especially at a time in our history when parents are spending less time with their children, and do not serve as much of a protective function as they once did. Psychiatry teaches that it is both nurturing and limit setting from parents that neutralize aggression in the young child.