It is, of course, possible to design a study that shows a connection between doctor fatigue and impaired performance.

WSJ: Should Medical Residents Be Required to Work Shorter Shifts?

The C30 Polestar's unprogressive behavior is by purely by design, and it raises a question all car buyers must answer for themselves: Where is the fatigue factor?

WSJ: 2012 Volvo C30 T5 R-Design Polestar Edition Review: The Spirit of Sweden Lives | Rumble Seat by Dan Neil