Fewer boys born in bad times, study finds
March 2, 2010
Lesley Ciarula Taylor
STAFF REPORTER
More than 3,000 boys weren’t born in California as a direct result of the economic shock of widespread unemployment, new research concludes.
“What we’ve demonstrated here is that the economy affects whole populations,” said Ralph Catalano, lead researcher at the University California Berkeley School of Public Health. “When the economy quivers and shakes, everybody has to adapt.
“We’re arguing that understanding the economy as a shared environment for humans is important.”
Specificially, the researchers took data of the number of male and female births in California from mid-1995 to the end of 2007. That was measured against U.S. Labor Department monthly numbers on mass layoffs in the state. A mass layoff is defined as 50 or more people filing for unemployment insurance from a single company over five weeks.
The researchers determined that the shock of expecting mass layoffs led to 3,090 males being spontaneously and involuntarily lost during pregnancy. The number of females born, according to their calculations, was unaffected.
“This particlar paper wasn’t meant to inform public policy or make pregnant women nervous,” said Catalano. “Humans anticipate what is going to happen to their security.”
In fact, he used Toronto as an example of how difficult it can be to trace the effects on a mobile population. “A significant percentage of the population of Toronto had their gestation elsewhere, in different circumstances,” he said.
While previous research has tracked the effect of war, weather and calamity on births, this is the first study to measure the effect of an economic shock, he said.
“What this implies is that the characteristics of the next generation can be affected by the current environment,” he said.
Catalano explains what ancient reflex is in play: in good times, more males are born but some of them are not as strong. In past generations, the frailer infants may have had higher mortality rates. In difficult times, fewer but stronger males are born and “appear to enjoy relatively longer life spans on average.”
Their paper, “Selection in Utero: A Biological Response to Mass Layoffs,” has just been published in the American Journal of Human Biology.
Featured Sponsored Listings