Old home movies are a fascinating source for how people actually danced in the past. This is a great clip of a New Year's Eve party in 1963 - not even sure where, it looks North American (the clip was posted by Candadian-based Fun with Stuttering)
One of the things that interests me is at what point did it become acceptable for a single woman or man to go out on the dancefloor and dance on their own - without being asked to do so by and with a member of the opposite sex first (chiefly by a man asking a woman)? Before the Second World War, social dancing in Europe and America seems to have been very much 'couple dancing'. Perhaps jitterbugging/jiving was a transitional point - while the dancing was still couple based it did not require the constant physical contact between dancers. I have found references to women dancing on their own, or with each other, in London during the war.
In this 1963 film, there are couples dancing but also people dancing on their own, or rather dancing as part of a group without being attached to a member of the oppiste sex. There is a woman on the edge of the group doing the Twist in her own space, and two women doing the Twist opposite each other. So perhaps the Twist was a step towards the modern dancefloor, where by the disco period couple dancing was confined largely to the slow dance at the end.
Pop Feminist tells me she's doing some research on the Twist, look forward to seeing what she comes up with.