So how do you pitch it? Do you go like "alright, you've overcome the single most obvious manifestation of irrationality, now how about all the other ones?" Or do you make any other attempt to tie rationality into their core purpose?
I find it's helpful to pitch rationality by tying it to reason. "Reason" is something that secular people feel warm fuzzies around, and so starting from what they know and like works well. From reason, it's easy to transition toward what it would be reasonable to do, namely be reasonable about how our minds work and how we should improve them. For example, check out this video of a presentation I made as a Rationality 101 for Secular People.
IMO trying to sell rationality to people is like trying to run a corner shop that sells nonalcoholic beer, sticks of celery and bottles of springwater.
Sure, we all know it's good for you, but the place across the road is selling Mars Bars, Budweiser and Marlboros.
The memes and ideas that get (most) people excited are not the careful, cautious ideas of map-territory rationality. Personally, I like map-territory rationality, it excites me, but I realise that I am a bit of a freak because of this.
I hear you, which is why it's important to wrap rationality in forms that make it look like Mars Bars. Here is one example of how I do this. As you can see, this piece was shared over 1K times, so pretty popular (the baseline average for that site is around 100 shares).
It seems like the target audience in this case are secular groups like atheist groups. Atheists groups currently form over being against theism which gets boring with time. I think those groups should be open to rationality if the pitch is right.
The Less Wrong meetup in Columbus, OH is very oriented toward popularizing rationality for a broad audience (in fact, Intentional Insights sprang from this LW meetup). We've found that doing in-person presentations for secular groups is an excellent way of attracting new people to rationality, and have been doing that for a couple of years now, through a group called "Columbus Rationality" as part of the local branch of the American Humanist Association. Here's a blog post I just published about this topic.
Most importantly for anyone who is curious with experimenting doing something like this, we at Intentional Insights have put together a “Rationality” group starter package, which includes two blog posts describing “Rationality” events, three videos, a facilitator’s guide, an introduction guide, and a feedback sheet. We've been working on this starter package for about 9 months, and finally it's in a shape that we think it's ready for use. Hope this is helpful for any LWs who want to do something similar with a secular group where you live. You can also get in touch with us at info@intentionalinsights.org to get connected to current participants in “Columbus Rationality” who can give you tips on setting up such a group in your own locale.