Humans didn’t evolve to count so numbers remain a challenge
Sign on to any news website and you’ll see them: The million-plus votes a winning candidate received. The billion-plus dollars found in some state or city’s general fund.
Our public discourse is filled with stats. We are bombarded daily with numbers in the millions and billions, especially where money is involved. If those figures seem hard to comprehend, or even imagine, it may be because humans did not evolve to count and multiply.
“We are a species that has been around for 250,000 years and numbers have not been around that long,” said Rafael Núñez, a professor of cognitive science at UC San Diego.
Núñez calls the use of numbers “exact quantification.”
He said that while knowledge of numbers doesn’t always rely on human literacy, it is a recent invention and numbers beyond four or five are not even used by all humans on earth today. Numbers can quickly become confusing. And saying, for instance, that 1 million Americans have died of COVID-19 doesn’t necessarily mean much to the people who hear it.
“It becomes an abstraction and then the abstraction serves many purposes for doing science, economics and many things,” Núñez said. “But for really communicating in a meaningful way the tragedy in the case of the sickness and COVID — to communicate the tragedy, the number itself doesn’t provide that.”
Research by Núñez and others shows that humans and other mammals like dogs and chimps have evolved to discriminate between different quantities. They know the difference between a lot and a little and pre-literate humans have language to describe the difference.
But a study of Australian aboriginal languages showed their numbers had an upper limit of between three and five. Without creating symbols that refer to precise numbers, we have no innate ability to count any higher than that.
“We have a biological apparatus supported by very specific forms in our nervous system that has evolved biologically to discriminate quantities,” Núñez said. “But discriminating quantities doesn't mean language. It doesn’t mean we say ‘that is two and that is three.’ It doesn’t reflect the property of numbers. It’s just a discrimination of quantities.”
And that inexact discrimination of quantities is something we do all the time. For example: How many people showed up for that ballgame last night? A lot!
“Or even you can use other resources like vowel extensions or pitch. When you say Many! Many!” said Núñez, raising the pitch of his voice. “All of these combinations allow you to quantify in the natural world in a very effective way without having to have numbers.”
Some scholars have argued that our ability to distinguish quantities, a lot versus a little, indicates humans evolved to create and use numbers.
Rafael Núñez disagrees. He said that’s like saying our ability to walk and balance on two legs means we evolved to snowboard. But snowboarding requires training and a cultural underpinning. Just like it does when we’re using numbers.
Dean Nelson, director of the journalism program at Point Loma Nazarene University, said the best way for humans to understand numbers is to illustrate them.
“When l was growing up it used to be: If you stacked a billion dollars in (20 dollar bills) it would be the Empire State Building,” said Nelson. “I find those kinds of equivalents to be pointless. I think you have to look at it more as purchasing power.”
Let’s say, for instance, the cost of one fighter jet would equal the cost of a 1,000-person army battalion for five years.
Western water agencies figured out the need to illustrate quantities by inventing the acre foot of water, which is the amount you’d need to cover an acre of land with water that's a foot deep.
“The responsibility for us in journalism is to take numbers that we actually need to understand how our society is working,” Nelson said “Our job as journalists is to take those numbers and put them in some kind of a narrative form so that they’re comprehensible.”
A local scientist explains how we process numbers.
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