The Science Of Sibling Rivalry

Peter Toohey mulls it over:

[Animal behaviorist Scott] Forbes describes how herpetologists, ornithologists, and mammalogists found that “infanticide – including siblicide – was a routine feature of family life in many species,” most commonly seen in birds. Some birds lay two eggs “to insure against failure of the first egg to hatch. If both hatch, the second chick is redundant to the parents, and a potentially lethal competitor to the first-hatched progeny.” The healthy older chick often kills the younger to eliminate the competition, and some parents actually encourage siblicide when the death of the nest-mate doesn’t naturally occur.

After all, if resources are scarce, it’s better that the strongest offspring survive and that their potential efforts go to ensuring that happens. (It’s the old story of genetic replication again: Surviving offspring are more likely to have the strongest genes, and they are the ones that have the best chance of reproducing later and passing those genes on.) Forbes thinks that such extreme jealous reactions are not common in the human species, but “the more modest forms of sibling rivalry that are ubiquitous in species with extensive parental care – the scrambles for food and begging competitions – resemble more closely the dynamics that occur in human families.”

Update from a few readers:

That Youtube video of the two kids just sent me back about 30 years.

My older daughter and her brother had been fighting a lot one day and my husband made them sit on the couch and hold hands for five minutes. Somehow holding hands didn’t seem quite as hard to get done as hugging, but after about two minutes the giggles started and by the time the timer went off, they became again the power of two against the power of parents and ran off to play … not nearly as dramatic but just as successful. The two of them still talk about it once in a while. I have to admit my husband was much more creative in making certain that our kids suffered the consequences of their actions much better than I did.

Another is dismayed:

That gruesome Youtube of children forced to hug each other made me ill.  The boy was obviously overtaxed and needed rest.  The daughter has obviously learned her parents’ game well enough to work the problem.  But there is no love here. Neither child cares about the other; in the end, they only want to make it stop.  And the parents are nasty control freaks who have no empathy for either child.  That was billed on Youtube as “funniest punishment ever.”  It was actually one of the most manipulative and unkind representations of parenting I have ever seen.  I wonder what messes these children will become as adults, but I can guess.  The daughter will be able to game any situation and be a master of manipulation and control, having learned well from her parents.  The boy will finally catch on to how to work it, especially when he gets some testosterone and becomes aggressive, but he will always be a needy, dependent mess underneath.

When a hug is punishment, then black is white and up is down.