People thought the human body could not run a mile in less than four minutes until Roger Bannister did it in 1954. Once he had shown it was possible, two months later two other runners did it in the same race.
I've heard this a million times, but is it true? Nearly every athletic record from that era that was feasible to break has been broken since — usually multiple times — but we tend to ascribe those new records to better nutrition and medical/physiological/kinesiological progress [and steroids] rather than a psychological cause. Why would this one be any different?
And that's kind of how the rest of the article goes… a just-so story about why children of adults of low socioeconomic status often end up in low socioeconomic strata. It seems like lack of availability of similar educational opportunities (for one) at least warrants a mention.