We've heard of the "seven-year itch," but the news of a newly discovered septennial rhythm had us wondering if someone might not be pulling our ears. According to a recent issue of the British Medical Journal, a pair of European researchers have announced their latest finding: Not only do human ears keep on growing into adulthood, they show the fastest rate of growth every seven years.

Ears: A growth spurt every seven years

Jos Verhulst of the Louis Bolk Institute in the Netherlands and Patrick Onghena of the University of Leuven in Belgium reached their conclusion after calculating the "mean ear length" of British men ages 30 to 83. The researchers, by the way, were originally drawn to the subject by the ears, so to speak, following up on earlier work by a British researcher showing that older men have bigger ears. Of course, the findings could be peculiar to men -- or just to British men. But that would be cur-ear-ous indeed.

The idea of seven-year cycles in human development is as old as the Greeks, note Verhulst and Onghena, who have also discovered a circaseptennial, or almost seven-year, rhythm in the closure of the cranial suture. Might not the nose and other parts of the anatomy also show rhythmic growth?

"The claim of a seven-year cycle in the growth of men's ears may be the tip of some iceberg," says John Burns, a biology professor at Bethany College in West Virginia and the author of Cycles in Humans and Nature: An Annotated Bibliography. "Who knows what we will discover when we look beyond circadian, menstrual, and seasonal cycles in human biology? Our larger temporal structure is a vast unexplored domain. Pythagoras, Cicero, and Seneca suggested that such cycles exist, but decades of work are needed to resolve the reality and significance of seven-year and other long-term cycles."

--Patrick Huyghe