A friend's father, who is a software engineering manager, said, emphatically, "The number one cause of scheduling overruns is scheduling pressure."

Where does the research stand? Is a moderate amount of scheduling pressure invigorating, or is the manager I mentioned right or wrong, or is it a matter of "the more scheduling pressure you have, the longer the delivery time and the more TCO?" Is it one of those things where ideally software engineering would work without scheduling pressure but practically we have to work with constraints of real-world situations?

Any links to software engineering literature would be appreciated.