If the Lark/Gent is used to a Butterfly promenade and puts their right hand on the Robin/Lady's shoulder, while the Robin/Lady expects a Courtesy Turn promenade and puts their right hand behind their back, the dance doesn't flow as well as if they both immediately put their hands in the place the other is expecting. This means each dance will typically settle into a consensus position. And because people are more likely to travel locally than farther away, these positions will have regional patterns. This is very similar to the constraints on language, hence the analogy to dialects and why the Linguistics department accepted my thesis.

Over the past fifteen years I'd observed some changes, but I was curious what this looked like more broadly so I ran an online survey to gather some data. Here's what I found:

(On the 2023 chart the size of the dots indicate the number of survey responses they represent. The code is on github.)

This has felt like a big change to me. I remember New England having a very strong "we don't do hands on right and left through" culture (with the exception of Maine, which I didn't get to in 2008 but was well known for using hands) and then as it changed I remember feeling conflicted about whether to go along with it. I think part of what's happening is that when someone offers their hand out to you it feels pretty rude not to take it, so the variation spreads. Maybe the closest analogies in language are disrespectability cascades?

It looks like the Skater's promenade has been expanding? I think this is another one driven in part by the mechanics of dancing: when someone puts their hands in front of you it's easier to see what's going on, and Skater's is also slightly better at offering opportunities for interesting variations.

It's hard to tell what's been happening from this map since I have too little 2008 data from the South. My impression is that the South is slowly moving to the wrist grip stars used in the rest of the country, but I'd be interested to hear from long-time Southern dancers!

(More posts to come on the rest of the survey data.)