The earth is now home to over seven billion humans. If you find that hard to fathom, try grasping how many have ever walked the planet.
That’s what American demographer Carl Haub wanted to find out when, in 1975, he heard someone say that 75 percent of the people who’d ever been born were alive at that time.
Dubious, he set out to disprove it, taking two main things into account: (1) the assumed dawn of humanity and (2) average populations at different periods of time.
Using 50,000 B.C. as his starting point, Haub applied crude birth-rates—the number of annual births per thousand people—to each population set, then added them. His estimate? In 1975, 103 billion people had lived, but only 4 percent of them were alive at that time.
Applied to our current population, says Haub, those numbers are around 108 billion, and 6.4 percent. Mind-boggling, indeed.
Information and graphic from National Geographic
How To Confuse A Moral Compass
Research shows that people can be tricked into changing their opinions on moral issues and will even go so far as to defend these opposing stances.
Researchers had 160 volunteers take a survey in which they answered questions regarding their moral opinions on a set of issues.
”But the surveys also contained a ‘magic trick’. Each contained two sets of statements, one lightly glued on top of the other. Each survey was given on a clipboard, on the back of which the researchers had added a patch of glue. When participants turned the first page over to complete the second, the top set of statements would stick to the glue, exposing the hidden set but leaving the responses unchanged.
Two statements in every hidden set had been reworded to mean the opposite of the original statements. For example, if the top statement read, “Large-scale governmental surveillance of e-mail and Internet traffic ought to be forbidden as a means to combat international crime and terrorism,” the word ‘forbidden’ was replaced with ‘permitted’ in the hidden statement. Two statements in every hidden set had been reworded to mean the opposite of the original statements. For example, if the top statement read, “Large-scale governmental surveillance of e-mail and Internet traffic ought to be forbidden as a means to combat international crime and terrorism,” the word ‘forbidden’ was replaced with ‘permitted’ in the hidden statement.”
When the volunteer survey-takers were asked to read back their responses, about half of the participants did not realize that their answers had been changed, and nearly 70% accepted at least one of the altered statements. Of the volunteers, 53% even argued for the opposite of their original opinion on at least one of the answers.
Researchers have recorded the same effect in other areas, and have dubbed it “choice blindness.”