This surprising answer is the view of evolutionary biologist David Haig. According to
Science Magazine, Haig says that the baby who demands to be breastfed in the middle of the night is preventing his mom from getting pregnant again.
Haig explains that to the crying child, another baby means having to share mom and dad, so babies are programmed to do all they can to thwart the meeting of sperm and egg. Frequent interruptions in the night make both parents tired, and lower the chance of both parents having sufficient energy to seek to make another baby whilst their demanding child is of a certain age.
Haig also goes onto consider gene mutations and how these can change the patterns. Genetic disorders that are inherited from mothers or fathers provide even more evidence. Babies who get certain genes from their mothers sleep longer in the night, which is in the best interests of a woman who wants to get pregnant again. But babies who get the same genes from their fathers wake up more often, delaying ovulation in their mothers.
Haig’s theories are interesting, although there cannot be wholly proven and other biologists take
different viewpoints.
The new theory has been
outlined in the journal in
Evolution, Medicine and Public Health, in a paper titled “Troubled sleep: Night waking, breastfeeding and parent–offspring conflict.”
