It seems understandable that in a day and age where almost every decade is different from the next, we see a measurable cultural divide amongst generations. Off hand I feel it has a lot to do with technology. Therefore, it would stand that past generation held more of a cultural unity amongst generations with the slow changes in technology...but I dont know for certain.
Our time is not the only one when rapid changes have occurred in a society, though. I don't know if complaining about the new generations is one of those things that appear as a constant throughout history, but it certainly isn't exclusive to us. Take for instance this fragment from the Hojoki, Account from my Ten-foot-square Hut, written in 1212. The context for this quote is the author talking about the relocation of the capital from present day Kyoto to Settsu province.
When one looks at the road, those who should be on carriages, are riding horses; many of those who should wear court costumes or hunting robes are dressed like commoners. Manners in the Capital have certainly taken a turn for the worse. They're no different from uncouth rural warriors. As expected, we hear omens about chaos in the world. The days keep going by, but our society is agitated, and the hearts of men are not in peace.
Edit: A word.
I beleive Socrates wrote/said something complaining about the youth of his time, although I haven't ever found a reliable source to it.
"The children now love luxury; they have bad manners, contempt for authority; they show disrespect for elders and love chatter in place of exercise. Children are now tyrants, not the servants of their households. They no longer rise when elders enter the room. They contradict their parents, chatter before company, gobble up dainties at the table, cross their legs, and tyrannize their teachers." -Socrates
In a hurry, but isn't one of the earliest fragments of sanscipt writings some guy complaining about his son specifically and youth in general.