"But if everybody else has vaccinations they'll be fine."

"Some people have allergies to vaccinations, and they are not perfect, just very very good. A population where everyone is vaccinated will have no diseases but in a population with only some vaccinated people, even a few of the vaccinated people will get sick once the unvaccinated ones do. Also the government does not think one-year-olds should get to decide whether the risk of being sick is worth it, so even if it didn't affect anyone else they would not let you decide."

"It's not that I think they should let me decide it just sounded like they also wouldn't let you."

" - well, not all parents should get to decide that either, some might believe silly things and make bad choices. You could let blue and green and yellow parents decide, I guess, if it only affected the children."

"Why just those?"

"Smarter and more educated, and while some people of those castes would make bad judgments that hurt their children others would make good informed judgments that were better than a uniform law for their children, and I would expect it to balance out even or maybe positively. There are also community effects - if everyone around you is smart and has good judgment, then even if you personally are not very smart or thoughtful, you can make good decisions just by listening to them. In the castes which are not as smart or educated there would still be people who could make better decisions than the law, and people who could make worse, but I expect the balance to be in the opposite direction. 

Oranges might be just as good as green and yellow if we were talking specifically about medical decisions, since oranges know the most about medicine. If I were making a rule just specifically about medical decisions I would definitely put orange in the category of people who would make them well and informedly. If we were making a rule about something else I probably would not.

And in less educated and informed communities, the community effects go the opposite way - if lots of people around you believe some conspiracy theory, and you don't have the time or education or judgment to evaluate it yourself, you might just believe what they do, and so bad ideas can be very persistent."

"Why are some people less educated and smart?"

"People vary a lot in intelligence and as a result it varies how much school they want to go to and what it makes sense for those schools to teach."

"Oranges are teachers, don't they have to know a lot, not just medicine?"

"The majority of oranges are actually healthcare workers or home care assistants to elderly people, but oranges who are teachers learn lots and lots so they can teach effectively, yes."

"...and you said healthcare stuff would also help if it was a healthcare decisions rule."

"Yeah. There are other complicated things here, like if you make a law that affects more than half the castes but not all of them then the other ones will feel slighted and so you try not to do that, but it would be a good idea to give oranges special authority on healthcare decisions."

"Why is it 'more than half the castes'?"

"So everyone understands that it makes sense to have different rules for different people with different needs, but if it starts to look like everyone but them gets a better deal then they worry that the people making that deal think less of them, and they get angry or scared. If we change something for greens, that doesn't say much about how we see purples, but if we change something for blue and yellow and green and orange then that does say something about how we see grey and purple and they'll worry more. People try to avoid that by extending privileges in a way that doesn't make anyone feel singled out."

"Huh. That's complicated. Aren't most people purple?"

"Yes."

"So it's not about how many people you're saying the thing about?"

"No. It's about which castes, because credit allocations are by caste and so if the people making laws seem to be disfavoring your caste maybe they will cut your credits down the road."

"Oh."

"Having the best laws is important but so is everyone knowing that they are valued."

"And they won't just believe you?"

"People usually wouldn't say 'we don't really value you and we're going to issue you fewer credits' even if it's true, so saying that it's not true is not very convincing."

"Oh."

"Anyway, vaccinations are too important to let anyone decide for themselves even if they're very smart and good at decisionmaking."

"Maybe they will look okay."