Yeah, I've heard this too, but it conflates two different things.

Yes, it's possible for trauma to alter DNA. But that's not the same as saying that trama is heritable. There is no gene for "I don't like it when people call me the n-word," or "I grew up during segregation."

Our life experiences don't seep into our children through our DNA, they seep into them through the examples we show and fail to show them. Through the stories we tell them about themselves and the world they live in. Which is why I think it's so important that we're extremely careful about the ideas we pass on to our children.

The world we live in today is different to the world of 60 or 100 years ago. And children deserve to know that. They deserve to live in this world fully, instead of dealing with the baggage of our undeniably terrible history.

I don't expect a black person who lived through segregation to reason themselves out of their trauma responses (though I hope they can overcome them). But a black child born today doesn't have trauma responses. And I don't want them to grow up fearing a world that no longer exists.