This article is about the neurobiology of developing animal brains (WSJ Online, 10/27/09).  And because it's about laboratory animals, it can't be extrapolated to humans.  Still, when neuroscience seems to corroborate sociology, it's easy to want more.

 It seems German scientists have been doing controlled experiments on degus, a rodent related to chinchillas.  Degus are biparental creatures, meaning that both parents take part in raising young.  The German researchers raised a set of degus with two parents and another set with just the mother, the father having been taken away the day after the pups were born.  At 21 days of age (90 days is maturity in degus), they examined the pups' neuronal growth and compared the fatherless and biparental pups.  They also observed the behaviors of pups raised with both parents and those with just a mother.

It turns out that fatherless pups exhibit significantly different neuronal growth patterns than do their peers raised with fathers.  Their behavior is much more aggressive and anti-social as well.

The article mentions that Canadian studies have shown similar behavior in voles raised without fathers.  Voles too are biparental.  (One possibly misleading statement in the article says that only 10 percent of species are biparental.  That may well be true if all species are counted, but about 40% of mammal species, including humans, are biparental and over 90% of birds are.)

One of the German researchers, Dr. Anna Katharina Braun, explained,

The basic wiring between the brain regions in the degus is the same as in humans, and the nerve cells are identical in their function. "So on that level we can assume that what happens in the animal's brain when it's raised in an impoverished environment ... should be very similar to what happens in our children's brain," Dr. Braun says.

The behavioral changes seem to result from changes in the amygdala and the orbitofrontal cortex.

The balance between these two brain parts is critical to normal emotional and cognitive functioning, according to Dr. Braun. If the OFC isn't active, the amygdala "goes crazy, like a horse without a rider," she says.

Do human children raised without fathers exhibit similar differences in neuronal growth?  Certainly the sociology that deals with children of single-parent families clearly shows the behavioral damage fatherlessness can do.  Would it be a surprise that physiological changes in the brain were at the root of those sets of behavior long recognized by sociologists?

For example, one thing I'd like to know is whether fatherlessness has anything to do with the increased diagnosis of ADHD.  One of the three sets of behaviors that are diagnostic of ADHD is impulsiveness, i.e. the "horse without a rider" type of behavior.  Also, the rise in the diagnosis of ADHD began as significant out-of-wedlock childbearing and fatherlessness generally began to become an important feature of our social landscape.  Finally, the brain physiology of ADHD includes, among other things, smaller prefrontal cortex structures in children diagnosed with the condition.  Could that be the human counterpart of what Dr. Braun and her colleagues have discovered in fatherless dugus?

Obviously, I don't claim to know that ADHD has a connection to fatherless upbringing.  To date, there's no proof of that.  But it's intriguing enough for me to be eager to follow the research that is sure to come.    

This entry was posted on Thursday, October 29th, 2009 at 2:16 pm and is filed under Uncategorized. You can trackback from your own site.