Just watched the movie 42, about Jackie Robinson's beginning in baseball. One of the (very obvious, but that's ok) themes is the effect this has on children, seeing what the people around them are doing. The effect on both black and white kids at seeing the first black ball player; kids seeing Robinson called a n****r etc. I's not a heavy deep idea--that racism, and anti-racism are passed to children--but it's one of those ideas that's so important it bears repeating and repeating.
"Political correctness" is sometimes critiqued because though it restricts people socially it doesn't change them inside. But children are taking in what they hear around them, and if they don't hear hatred, there's less chance they'll hate too. Appearances matter.
In grad school I knew someone who was studying the effects on young women of seeing women politicians on TV etc. And apparently it makes a real difference, it affects what girls want to grow up to be.
In the Buffy series finale (spoiler) to fight off the Nosferatu-on-steroids army...
she finds a way to transmit her slayer strengths to all the Slayers in Waiting around the planet--which normally happens only when the slayer dies, and to one girl. Not only does this give the potential girls around her power, but we flash to scenes all over the world of shy or abused girls suddenly filled with slayertude.
That's what I imagine it's like when you're a child and you see for the first time that women can also be ass-kickers, or astronauts or pirates. I loved Charlie's Angels and Wonder Woman and Angelic Huston in Ice Pirates, and Marion Ravenwood, and Princess Leia. They widened for me the possibilities of what women can be.
You can't underestimate the effect Jackie Robinson had on society, just by showing up. It was a good sub theme.