Business Insider published an outstanding biography of Marissa Mayer that I just discovered last night and couldn’t stop reading.

It’s absolutely fascinating and I highly recommend it if you have any interest in Marissa or what’s been happening at Yahoo since she took over – but set aside 45 minutes because it’s long!

One interesting thing that stuck out was that apparently she only sleeps four to six hours per night.  I did a little Googling that seemed to confirm this.  She says she recharges by taking a week vacation every four months.

Apparently 1-3% of the  population can get by on just a few hours of sleep per night.  The Wall Street Journal wrote an interesting article about this back in 2011:

Natural “short sleepers,” as they’re officially known, are night owls and early birds simultaneously. They typically turn in well after midnight, then get up just a few hours later and barrel through the day without needing to take naps or load up on caffeine.

They are also energetic, outgoing, optimistic and ambitious, according to the few researchers who have studied them. The pattern sometimes starts in childhood and often runs in families.

…

Not only are their circadian rhythms different from most people, so are their moods (very upbeat) and their metabolism (they’re thinner than average, even though sleep deprivation usually raises the risk of obesity). They also seem to have a high tolerance for physical pain and psychological setbacks.

I remember reading about Jack Dorsey working full time at both Twitter and Square, leaving him with only 4 – 6 hours of sleep each night.  And there are other examples of well-known business leaders who claim to get by with less sleep than the rest of us.

I wonder if Marissa is sleep deprived or not.  If not, I can’t help but wonder how much of an advantage it is to need less sleep.  For someone as smart and as motivated as Marissa, those extra hours could be extremely productive hours – and I bet they are.

Which raises that uncomfortable issue about success and hard work.  It’s unfortunate but true that working harder for longer – if you don’t get burnt out – produces results.  But most people cross the point of diminishing returns at some point around 6 – 10 hours of hard and/or creative work per day.  And theres lots of discussion and evidence that some slack is necessary for creativity to flourish.  However Marissa is not known for her creativity, but rather for her attentive concern for the user experience and for the data behind product decisions.  For Marissa, working smarter vs longer may simply not be a tradeoff, and she can work harder and longer than most.  Which would help to explain why she’s at the helm of a multi-billion-dollar business and seems to be doing very well there.  Long may she reign.