I am NOT an expert, but I believe (West?) African dance emphasizes keeping the back straight, shoulders back, and the neck in line with the spine, even when bent over at the waist and with bent knees. Slouching is not a position of strength, after all. Personally, taking ballroom classes is what inspired me to figure out how to improve my posture. But I had to do a lot of the work on my own. For months of classes I basically forced myself into an artificially straightened posture that I thought the teachers wanted, until I accumulated enough information from multiple teachers, including some privates, on what my muscles (particularly lats/delts) were actually supposed to be doing and started to be able to maintain good posture most of the time without tension. Because most of the time, teachers use external imagery (e.g. a string pulling you up toward the ceiling) that does not help you figure out how to actually use your muscles properly. Good posture is internal. I'm still not really there yet, but good posture is starting to be more consistent and comfortable for me. I also did a lot of neck stretches. At the same time, I was also taking lindy hop, west coast swing, argentine tango, and other dances, and discovering through classes and personal experimentation that while the lower body and arms changed a lot, the upper-torso posture that "works" in each is actually remarkably similar, if not the same. Furthermore, I think dances in which you move your torso/frame around a lot teach you to maintain tone in your postural muscles in various orientations, as opposed to just one orientation (vertical). "Range of motion" is a good thing in exercise, right? That being said, some swing teachers emphasize relaxation more than frame, so that could lead to slouching. And again, I'm so not an expert. But personally, I am striving to keep as much lat/delt tone in swing as I do in ballroom, if for no other reason than my back really starts to hurt if I don't.