‘Huzzah! I may finally be vindicated for all those wasted morning hours I”ve spent sleeping in while others slaved at their breakfast meetings and morning classes. The BBC reported research in 1999 that correlates sleeping later in the day with higher levels of the stress hormone cortisol. Another report released yesterday, also reported by the BBC, indicates that higher levels of cortisol may slow-down or even completely halt production of new neural connections. In other words, sleeping in may not only make you a happier person, but also a smarter one.