If you’ve ever wondered why your newborn seems hardwired to cry for hours while your friend’s baby settles easily, new research suggests the answer might lie in their genes.
Researchers have discovered that DNA accounts for a large portion of how much babies cry and how easily they calm down.
The findings might provide some reassurance for exhausted families, who feel like they’ve tried everything to get their youngster to settle.
However, it suggests that not much can be done to combat the issue.
The team, from Uppsala University in Sweden, tracked 998 twins at two months and five months old.
By comparing identical twins, who share 100 per cent of their DNA, with fraternal twins, who share around half of their DNA, they were able to separate genetic influences from environmental ones.
The researchers asked parents questions about the children’s sleep, crying and ability to settle.
Their analysis, published in the journal JCPP Advances, revealed that at the age of five months genetic factors explained up to 70 per cent of the differences in crying duration among babies.
Researchers have discovered that DNA accounts for a large portion of how much babies cry and how easily they calm down
The findings might provide some reassurance for exhausted families, who feel like they’ve tried everything to get their youngster to settle
Dr Charlotte Viktorsson, postdoctoral fellow in psychology and lead author of the study, said: ‘What we found was that crying is largely genetically determined.
‘At the age of two months, the children’s genetics explain about 50 per cent of how much they cry. At five months of age, genetics explain up to 70 per cent of the variation.
‘For parents, it may be a comfort to know that their child’s crying is largely explained by genetics, and that they themselves have limited options to influence how much their child cries.’
The study found a baby’s ability to settle down was also largely determined by their DNA, accounting for up to 67 per cent of the variation between infants.
‘How rapidly the infant settled was primarily due to the environment at two months of age, but by five months their genetics had gained some significance,’ Dr Viktorsson explained.
‘This reflects the rapid development that occurs in infants, and may indicate that parents’ efforts in getting their child to settle may have the greatest impact in the first months.’
However, genetics played less of a role when it came to how many times the children woke up during the night.
This was mainly influenced by environmental factors, they discovered, such as sleep routines and the environment in which the child sleeps.
Researchers from the RIKEN Centre for Brain Science in Japan claim that the trick to soothe a crying infant is carrying them in your arms for five minutes, then sitting with them in your arms for five to eight minutes, before placing them in their crib
A study has previously claimed to have the ‘recipe’ to lull a baby to sleep – and it’s surprisingly simple.
From offering a pacifier to desperately singing lullabies, most exhausted parents will go to any lengths to get their baby to stop crying.
But researchers from the RIKEN Centre for Brain Science in Japan claim that the trick to soothe a crying infant is to carry them in your arms for five minutes, then sit with them in your arms for five to eight minutes, before placing them in their cot.
The team hopes the method will provide an immediate solution for crying infants, although they’re unsure whether it will improve sleep in the long-term.
