Why the Childrens are being more notorious nowadays?

Why the children are being more notorious nowadays?
The children's in our grandfathers generation are more simple obeying kind of nature and shy but nowdays, most of the childrens are exactly opposite to these. And why this is happening I have some views.

I think just like we are becoming developed and see ourselves from going past to present and in future also. We are making society and world more happy and humorous and close to each other the culture is changing, peoples meet and laugh more and try to become more happy, lovable, extrovert than ambitious, successful and introvert nature. We see the change in family & relation bonding, more  friendships  and friends makes us more humorous, affable and extrovert and these qualities makes us more different than our past human and it also makes good changes into our genes and genetic structure which we transfer into our successor(just like other qualities and also genetic diseases)and i say that's why they become more notorious in childhood and in future the children are become more notorious making the ways better than the past human in every field and it also affects our knowledge and understanding that we become more mature in early ages of our childhood.
And if they get proper same kind of love from everyone and lives in the same happy world (and not a world which getting worse day by day) this things continues to grow and the world will become more happier and beautiful (and having more kind persons than the cruel ones).

I hope the last line will become true.