A swivel chair is a behavioral magnifier. Hence use it when you interview someone!
This concept is for example developed in the book ‘Spy the Lie‘: “It’s worth mentioning here that when we interview someone, the last place we would want the interviewee to sit is in a straight-back chair with four legs. We want the person in a chair that has wheels, that rocks and swivels, that might even have moveable arm rests. That type of chair becomes a behavioral amplifier, magnifying those anchor-point movements and making them particularly easy to spot.”
Even in meetings it is always interesting to watch how participants relate to their chair and use all the various degrees of freedom available. It can be extremely useful during negotiations.
Train yourself to observe people on swivel chairs, and observe yourself when you are sitting on one too!