GEOFF BENNETT: Marc Freedman is the founder and co-CEO of CoGenerate, a company seeking to bridge the divides between people of different ages.

Here, he shares his Brief But Spectacular take on age diversity.

MARC FREEDMAN, Founder and Co-CEO, CoGenerate: One of the most inaccurate and pernicious stereotypes about older people is that their best work is behind them.

There's a mismatch between the life course that we have inherited, which is you jam all the education into the first part of life, all the work into the middle and all the leisure into the end.

That model might have worked when life expectancy was 60 or 65.

But it's not designed for the new longer lives that people are already living and that will be extended even further in the future.

You can't simply work for 30 or 40 years and then live off it for another 30 or 40 years.

It's just not financially possible.

But it's also not psychologically viable.

Older people need what we all need, what Freud described as love and work, a sense of connection, of bonds that matter deeply, and a reason to get up in the morning.

But, for so many decades, older people have been consigned to a world that's both isolated and cut off from that sense of purpose.

We have consciously and systematically separated people by age.

After the turn of the century in the United States, we outlawed child labor.

We created high schools, and, all of a sudden, young people were in settings with other young people.

We created Social Security during the heart of the Depression.

So, each one of these measures had tremendous value.

But when you combine these policies and these innovations, the net effect is a grievous wound.

We have created a society where people of different ages have relatively little contact.

We're living in the most age-diverse society in history.

Half the children born in the developed world since the year 2000 are projected to see their 100th birthday.

That's twice the projection of a century ago.

And we're seeing already four, five, six generations living and working at the same time.

How do you learn to cooperate with someone of a different age if you don't have any contact with them?

So I think we need to hone our skills in working across generations.

And then we also need to develop opportunities for older, younger and people in the middle to mix in the context of daily life.

I think the key is proximity and purpose.

We need to rethink the institutions that have been designed for older people, and do it in a way which bring generations together for mutual benefit and for a greater sense of joy.

Society grows great when older people plant trees under whose shade they shall never sit.

My name is Marc Freedman, and this is my Brief But Spectacular take on how we can make the most of the multigenerational moment.

GEOFF BENNETT: And you can watch more Brief But Spectacular videos online at PBS.org/NewsHour/Brief.