They say that creativity loves constraints but experience suggests it’s not easy to know which ones it really loves and which it wouldn’t take to the prom.
Keith Sawyer reports some interesting research into the question: Do tight deadlines make you less creative? As with all such research the answer isn’t completely straightforward, but mostly, it’s no they don’t. The slightly more detailed answer is that some time pressures do work but only for certain people.
There’s often pressure in meetings and workshops to get to defined outcomes on a defined schedule. This research confirms my view that this can be quite toxic to creativity. Keith’s done a lot of research (see his book, Group Genius) on things like brainstorming which also suggests that intensity is much less productive than letting folks work reflectively and often on their own.