The graphic is interesting...a parallel to that used for representation of evolution itself. However, any notion of equality within the ages of man fails to establish a point. If, indeed, there was one to begin with. Which I doubt. See, ' child is father to the man' is merely quaint metaphor. At best. Worn-out aphorism, at best. 'Equal' is slippery. Equal, compared with what/whom? You just can't play it this way. Children are born, grow,live, grow old and die. This does not happen in reverse. Nor, should it.
What is really being asked here? Is this just an allegory? It is not about savant or prodigy, I think: exception is ANOTHER rule....though we do not dream it that way. As a practical matter, equal is that which has been earned. Not inherited. Or bestowed...

Juliana's book is too expensive for me (over a hundred dollars – cheaper on Kobo – but still… ouch.) Maybe PT could finagle a discount for PT subscribers? (Just saying.) I did buy Amia Srinivasan's book only to have the show canceled. Here is the free abstract on Juliana's book. She has several other papers out as well. I can post those public abstracts if anyone can't find them.

https://global.oup.com/academic/product/justice-across-ages-978019879218...

Justice Across Ages: Treating Young and Old as Equals

Juliana Uhuru Bidadanure
Abstract contained in quotes ==> “Age structures our lives... including families, workplaces, and schools.”.

“Age structures our lives and societies. It shapes social institutions, roles, and relationships, as well as how we assign obligations and entitlements within them. Each life-stage also brings its characteristic opportunities and vulnerabilities, which spawn multidimensional inequalities between young and old. How should we respond to these age-related inequalities? Are they unfair in the same way gender or racial inequalities are? Or is there something distinctive about age that mitigates ethical concern?

Justice Across Ages addresses these and related questions, offering an ambitious theory of justice between age groups. Written at the intersection of philosophy and public policy, the book sets forth ethical principles to guide a fair distribution of goods like jobs, healthcare, income, and political power among persons at different stages of their life. At a time where young people are starkly underrepresented in legislatures and subject to disproportionally high unemployment rates, the book moves from foundational theory to the specific policy reforms needed today.

If we are ever to live in a society where people are treated as equals, the book argues, we must pay vigilant attention to how age membership can alter our social standing. We should regard with suspicion commonplace forms of age-based social hierarchy, such as the political marginalization of teenagers and young adults, the infantilization of young adults and older citizens, and the spatial segregation of elderly persons. This position carries important implications for how we should think about the political and moral value of equality, design our social and political institutions, and conduct ourselves in a range of contexts including families, workplaces, and schools..”

The key idea is inter and intragenerational justice and equality, and age rights. That society is not up to science is probably always going to be true. Bidadanure has written on Universal Basic Income which might also play into the discussion. Hopefully, this can start some conversation.

I can tell you; this book seems centered on the younger generations. The older workers - not infantilized but indentured, without moral or economic luck, need liberation and distributive justice as well. I have an Amazon delivery person who is 20 years older than me, and I am not young.

I'm also interested in the science of human development. Children and the elderly need care and special rights. Juliana, I'm sure, comprehends all this.

Hit the link below for separate abstracts for each chapter from the table of contents.

https://oxford.universitypressscholarship.com/view/10.1093/oso/978019879...

Table of Contents

Introduction
Part One
1. Equality over Time
2. Lifespan Prudence
3. Relational Equality Between Age Groups
4. Treating Young and Old as Equals
Part Two
5. Age, Jobs, and Inequalities
6. Basic Income versus Basic Capital: A Temporal Perspective
7. Youth-ing Politics: A Defence of Youth Quotas in Parliaments

Equality, in many respects and under many circumstances, is an experiential passage. We gain it through our own efforts. Therefore, it does not attach to a particular age at a given time. Savants and prodigies are exceptional people whose powers of thought and reason outstrip age: they know;can intuit and infer, far more than 'normal' people. These talents appear to be evolving in humans: it appears we have greater numbers of children excelling in school than were obvious fifty or more years ago. Can it be that such individuals are indicators of an exponential aspect of evolution? I am pretty sure others are at least toying with such a notion.
Whatever the case, and, however things proceed, the idea of equality seems misplaced. To me. It just does not seem to square with emergent facts. And those are still in their infancy, so to speak.

Equality is a social contract we make, and I'm not sure to whom or with whom. I'm pretty sure it is made at birth and paid with your life on your death bed. It surely isn't earned. Equality is a right.

There are cohorts of young people today who are questioning the decisions of our generation (the boomers) while sticking their noses on their phones. There has never been a better time to be just and equal. The soaring price of housing and childcare make past injustice real today. It is about time to consider age inequality.

I thought more on the first sentence of the What is it? Intro to this post, and my remarks of October 31, 2021. I also re-read Mr. Smith's comments. My distillation boils down to the following: no, all ages are not equal, nor should they be. Unlike other modes of equality, race;color; national origin; sex; disability, equality, as it obtains for age, is earned, not summarily bestowed. Younger people, through observation, opportunity,experience and education, earn equal respect and treatment. If this seems radical or facially unfair to anyone, reading these remarks, I would encourage those kind souls to think carefully on their assessment.

An example:
No one can seek election to the office of President of the United States before reaching thirty-five years of age. If this seems arbitrary or cavalier in some way, it is, nonetheless, a long-standing specification of the job description. Is it excessive, outdated or unfair? Maybe so. But until successfully challenged and overturned, it will hold the force and effect of law. Crybabies need not apply.
There are dozens of other examples. This one seems sufficient.

Are children or the very old to be treated any-which-way-we-want? Of course not. We have laws proscribing such behaviors. Naysayers only learn through experience, education, observation and opportunity.

The blog post on age and ageism is partially addressed here and there. It is complicated. Why? Well, because as we grow older---gain knowledge and experience---our personal sense of worth accrues. There is, however, a tragic downside. Competition. Only the tenacious and determined among the older cohort are able to withstand, to overcome the determination to shut them out.
This is generational succession. I know, personally, fewer than five people, my age or older who are intellectually successful.. Fewer than that who are economically comfortable, intellect notwithstanding. Generational succession is how things are. People get old and die. Anything before that is gravy.. Or hog slop. The few friends I admire most never look back. This, more than anything, is why they go on. PSDP: providence smiles on determination and purpose. I have shared that platitude with my fifty-something ex-Navy, PTSD step son. Don't know how that will be work out.