Herman Pleij vertelt onzin over geboortegolven

Richard Udry of the University of North Carolina, debunked the theory in 1970. Instead of relying on an informal poll of hospitals as the Times had done, Udry conducted a more rigorous study of all New York City hospitals. The unromantic result? No statistically significant change.

Relying on general statistics showing that 90 percent of babies conceived on a specific date were born in a seven-week period some nine months later, he looked to the records for June 29 through August 16. He showed that in 1966 exactly 13.9 per cent of the annual births were counted within this period -- not more than in any other of the five previous years.

"For those who still imagine that all babies conceived on a given date are also born on an exact date 267 days later," he counted the total number of births for that day. The 431 births in 1966 fell just in the middle of a range from 406 (in 1964) to 497 (in 1962).