In a speech on the value of diversity in working life, Bank of England Chief Economist Andrew Haldane made an interesting observation.

"Humans are sentient, water-filled whoopee cushions moulded over millions of years of evolutionary experience," Haldane said in remarks published on Friday.

It's not the usual statement from a central bank, but then Haldane isn't a stereotypical central banker.

His speech — titled "The Sneetches" in reference to a Dr. Suess book about "an imaginary creature of which there are two types: those with and those without stars on their bellies" — touched on evolutionary biology and Renaissance Florence to explain how and why the Bank of England has tried to increase levels of diversity in its staff.

Along the way Haldane reveals some interesting details about how the central bank has changed since former Bank of Canada Chief Mark Carney took the reins in 2013.

"Of this year’s graduate cohort, only 40% has a degree in pure economics and finance. I say “only” because, as recently as 2009, the corresponding fraction would have been 60%. This year’s graduate cohort is drawn from diverse disciplines ranging from particle physics to aerospace engineering to ancient history. Disciplinary diversity is on the rise."

"So there are in total 16 possible personality types, typically summarised by a four-letter acronym. For example, I am an INTJ: Introvert, iNtuitive, Thinking, Judging.

"Although these 16 personality types are not uniformly distributed across the population, no one category typically comprises more than 12-14% and none less than 2-3%. Viewed from this vantage point, the Bank’s results were interesting. Around 60% fell into a single category: ISTJ. In 2006, ISTJ’s were the star-bellied Sneetches of the Bank of England. The chances of this occurring by chance in the population at large are far less than one in a million."