Would you consider a 50% death rate among your staff to be a serious problem? That’s typically how many sailors died on ocean voyages in the 1700s. Scurvy was the main killer, not enemy action. By 1747 a young Royal Navy surgeon found a scurvy cure. Yet 50 years passed before the Navy started adding a spritz of lime juice to the daily rum ration, to end scurvy. The story is a great example of how a mental process known as anchoring stops innovation in its tracks.
In 1740 Captain George Anson lead a squadron of 6 warships and 2 supply vessels on a round-the-world voyage in pursuit of a Spanish treasure ship. Of the 1,850 men who sailed only 180 men survived. That’s a 90% death rate. Scurvy is caused by not eating enough vitamin C. Your gums bleed, your teeth fall out, and then it gets nasty. The Navy brass were unsure of what caused scurvy but they knew it was crucially important to capture the treasure ship.
This is anchoring at work, the tendency of the brain to hunt for a reference point when it needs to make a decision. All facts are then evaluated relative to the reference point — NOT the absolute value of all the facts in total. Often the anchor is set early in the going, when you’re first learning about a subject. That is, you tend to give greater weight to things you learn first, and discount later facts.
So, back to Captain Anson and the Royal Navy brass. They were aware decades before Anson’s voyage that citrus juice seemed to prevent scurvy. And scurvy was known to kill far more sailors than enemy action. However the notion that nutrition had anything to do with scurvy was a completely foreign concept. For centuries all food was thought to be the same. As Bill Bryson wrote in At Home – A Short History of Private Life, “a pound of beef had the same value for the body as a pound of apples, or parsnips or anything else.” This was just one of the ancient and time-tested anchors that new ideas about scurvy prevention had to move.
The horrendous death rate of Anson’s crews was not unnoticed. It contributed to James Lind, a Royal Navy surgeon, testing out citrus juice as a scurvy cure in the late 1740s. On one voyage Lind divided 8 sailors with scurvy into 4 groups. He gave each group a different diet. Only one group got lemons and oranges. Only the sailors who got citrus juice recovered from scurvy. Pretty compelling proof right?
Wrong. Nothing happened. Despite Lind’s hard evidence, 50 years passed before the Royal Navy added lime juice to the regular diet of its sailors.
It wasn’t just that the Navy brass were especially stubborn. There was another anchor already set. England needed to finance an arms race with Spain. The threat of open war was constant. Spain held Central and South America. These territories were rich in gold and silver, far moreso than England’s colonies. Spain showed every sign of being able to outspend England. Then as now, arms races are terribly expensive. Lord Newcastle, the First Lord of the Admiralty, gave Anson one mission and one mission only. Steal as much Spanish treasure as he could, and get home. It was great strategy. It lessened Spain’s advantage and boosted England’s ability to keep pace in the arms race.
Capturing a treasure galleon was great strategy but fiendishly hard. In over 150 years of trying Anson’s capture was only the Royal Navy’s second success. Anson was given a hero’s welcome. Eventually the King made Anson First Lord of the Admiralty.