Someone well known among BDSM authors – sadly I don’t remember who – said that dominants don’t really come into their full potential until their 40s. In those years experience combines with maturity and raises them to the peak of their individual ability.
Do you see any validity to this or is it just ageism? Is there a correlation between chronological age and erotic domination?

That sounds about right to me.
It is a sort of ageism. Young people can’t see it because they aren’t there yet.
I am of the belief that until about age 30, people survive mostly on luck. After that, skill takes over.
For us older farts, there is some truth to the allegation that women do not recognize their domme potential until their 40′s.
For the boomer generation, girls grew up with the teachings that “nice girls don’t.” It was not until the kids grew up and were out of the house that they had enough time to discover themselves and some of them discover their domme side.
Having kids around puts a damper on one’s sex life, one’s kink life and one’s personal life.
I don’t think my mom was a domme, but she certainly became a much different (and more interesting) person after my sister and I left the nest.
My wife/mistress just turned 60 yrs old. She has been my DOMME for the last 40 yrs.
20′s SHE was good
30′s SHE was better
40′s SHE was terrific
50′s SHE was fantastic
60′s SHE is all of the above
Of course, i’m a little biased because i’m over 40 but, occasionally i’ll see web pages that advertise a 19 year old ‘dominant.’ A little difficult to take someone like that seriously, at that age most of us are still trying to find ourselves.
My girlfriend was in her 40s and she dominated me with her touching, pinning and tying up whenever I wore a bathing suite or t-shirt, shorts and barefeet so I think dominants really do come into their own in their 40s. I didn’t have a chance and she knew it.
I don’t see it as ageism but I do agree that many women do not come into their own until they are older. I wrote recently about becoming the older woman. While I have had dominant urges all my life, it was not until I got older that I could throw off those notions of “nice women don’t” and live the way I want without reservations. I have fewer qualms about making everyone else happy and I concentrate more on pleasing myself. It does get better as you get older.