Causes and Effects

What causes these proposed differences in generations?  

To introduce this, consider the different historical and social events recognizable by a 10 year old child (born 2005) 30 year old young adult (born 1985), or middle aged 50 year old (1965). None remember JFK. The youngest doesn't remember 9/11. The oldest was allowed (required) to walk to school as young as 8, while the youngest may be accompanied at all times, still. The middle one was a child when the Internet exploded with the invention of the World Wide Web. Experiences such as these impacted who they are and what they do. And many are shared across multiple years, so that say, those born during about 1982-2004 have much in common with this hypothetical 30-year old. 

Not only does it matter what events are shared but how old each was at the time. A child may quickly take it for granted that all information everywhere is instantly accessible. A major economic downturn affects the older person set in their ways differently from the child who can't really do anything but adapt to her family's change in income. We can expect that people who are in the same stage of life during particular historical events will have related outlooks. People are especially going to be impacted by what happened during their youth, which is to say about their first 20 years. The years right after that, when they are young adults starting families and careers, will largely complete their view of the world and how it works. If childhood is relatively stable (think 1950s) and young adulthood triumphant (Nixon resigns!) outlook will be different from a turbulent childhood (say the 1890s) that leads into mixed success as adults (like World War I). 

Bringing it back to my main goal here, these related outlooks are likely to affect how they view stories, whether in film or video or text.