In that case, I'd propose that if Annie is an adult she’s essentially unreachable. No matter how much effort you expend trying to coach her on basic rational skills she isn’t going to get it, because as a general rule adult humans simply don’t change their basic approach to life that radically. You’d have to replace her entire social milieu with a circle of rationalist associates to have any chance of getting through to her, and even then she’d probably just adopt the surface appearance of rationality as a sort of social-acceptance ritual.
So as a practical matter Barbara, Caroline and Donna are the people who might actually join, contribute to and benifit from a rationalist group, and the question becomes how to balance your appeal to all three instead of restricting yourself to Donnas.
This post grew out of a very long discussion with the New York Less Wrong meetup group. The question was, should a group dedicated to rationality be explicitly atheist? Or should it make an effort to be respectful to theists in order to make them feel welcome and spread rationality farther? We argued for a long time. The pro-atheism camp said that, given that religion is so overwhelmingly wrong on the merits, we shouldn't allow it any special pleading -- it's just as wrong as any other wrong belief, and we'd lose our value as a rationalist group if we began to put status above truth. The anti-atheism group said that, while that may be true, it's going to doom us to be a group exclusively for eccentric nerds, and we need to develop broad appeal, even if that's hard and requires us to leave our comfort zone.
Things got abstract very fast; my take was that we need to get back to practicalities. Different attitudes to religion have different effects on different types of people; we need to optimize for desired effects and accept what tradeoffs we must. We can't appeal equally to everyone. So I came up with a sort of typology.
The Four New Members
Annie