According to the research of Harvard’s David Haig, it’s conceivable that babies evolved to cry at night not necessarily because they need to be fed, but because, by doing so, they could well delay the arrival of siblings who would invariably compete for scarce resources.
In an attempt to explain why babies, especially those that are breastfed, begin crying more at night upon turning 18 months of age, Haig, an evolutionary biologist, has suggested that it might be in order to wake their mothers, thus prolonging lactational amenorrhea – the temporary postnatal infertility that is known to occur in nursing mothers.
As others have pointed out, there may be other factors at play. For instance, it could be argued that young children kept closer to their parents at night my have a better chance at survival, irrespective of whether or not the side effect is fewer siblings. Regardless, though, I just love thinking about this stuff. And Haig’s theory makes total sense to me… Of course, it also makes total sense to me that babies may just scream at night in order to keep their parents from having intercourse, in hopes of breaking them up, so that, in subsequent years, they might have twice the number of birthday parties, and Christmases with their birth parents and their respective new mates.
[Haig’s work, which was recently published in the journal Evolution, Medicine and Public Health, can be found here.]
9 Comments
Babies are monstrous little parasites.
by the time we reached 18 months of breastfeeding I was sleeping topless and never woke up for feedings because he just found the breast on his own. I didn’t even know this was a common occurrence for most babies at this age.
I’ve never read the Dawkin’s book “The Selfish Gene,” but I’m wondering if this might somehow be related.
I can totally see how a screaming baby, especially if it’s between a mother and father, would have a chilling effect on the baby making. I suppose, in the whole scheme of things, though, it would be worse. Some creatures on this planet devour their mates. We should probably be happy that babies, immediately after exiting the womb, don’t rip their father’s penises from their bodies.
A better image for this post perhaps.
http://imgur.com/FgqIkgu
More interesting evolution news.
Read more:
http://news.sciencemag.org/biology/2014/04/scienceshot-chameleon-vine-discovered-chile
That’s a stupid theory.
Perhaps babies of that age cry at night because they are hungry and the happy result is reduced fertility. Though I haven’t read the paper, I’ve read plenty of other stupid papers and, having a PhD myself and having no good ideas or theories, know full well that tenure and a degree don’t make for good ideas or theories.
The direction of causation here seems to be flawed.
Besides, unless you plan to have more children, you shouldn’t be having sex anyway.
Devote your time to something important like saving money for you childrens’ college expenses or saving for retirement.
Sex is for young, attractive people, not old people like us.
Is it accepted practice as an academic to weigh in on the merits of a paper without having read it first, Dr. Larson?
Also, who’s to say that the mothers aren’t having sex to save money for you childrens’ college expenses?