[davidvaughan]

For many people, sleep seems to be the #1 productivity booster. Certainly, the research seems to suggest focus suffers significantly thanks to lack of sleep - not to mention IQ.

Needless to say there seem to be exceptions - Margaret Thatcher famously coped with 4 hours a night. It's been suggested that some people's ADRB1 expression continues while they're awake, which means they need less sleep. However, less sleep is also associated with dementia late in life.

[sradman]

I never heard about the ADRB1 gene before. The expressed protein acts as a receptor for epinephrine and norepinephrine so it sounds like it plays a key role in regulating the sympathetic and parasympathetic nervous systems. It makes sense that variations in the gene impact things like sleep and stress.