I had brought up generation gap earlier, this is another look at the same thing from a different vantage point. And they don't contradict :-)
People are in different stages of evolution (for want of a better word) at any point of time. I would like to think of them as :
Generation Gap is quite literally a Generation/Development Gap!
"Generation Gap" happens when two people happen to be in different 'evolutionary stages which leads to a conflict of values and differentiated view points.
As examples :
If I am at the stage/generation where I value Independence and the other person is at a stage/generation where they value Inter-Dependence, I would take every effort by the other person for a synergistic relationship or mutual dependence as a threat on my Independence and react sharply. This is what I think is a "Generation Gap". Once I grow and start believing in the benefits of synergies without fear or threat, I would behave differently and in the process overcome the gap.
Same goes for a young child - still very dependent and the parent who is independent. Here too there is mismatch in the developmental stages which could lead to a lack of understanding.
Generation gap is a natural process and wanes (or grows) with time and experience.