Scientists at the Medical Research Council in the UK found that breastfed babies easily get irritated and cry more compared to formula-fed babies, who appear to be more content and easier to pacify.
The most common reason mothers often give for stopping breastfeeding is that “Breast milk alone didn’t satisfy my baby”, which the scientists said reflects their perception of irritability as a negative signal.
But, they said, this crankiness in babies is normal and just their natural way of communicating their needs to their mother and is no cause for alarm.
For example, some cries will be down to tiredness not hunger. And the reason formula babies are so serene could well be because they are overfed, they added.
“Bottle-fed babies may appear more content, but research suggests that these infants may be over nourished and gain weight too quickly,” lead investigator Dr Ken Ong was quoted as saying by the BBC News.
“Our findings are essentially similar to other stages of life; people often find that eating is comforting.”
In their study, the researchers asked more than 300 mums to comment on the temperament of their own baby and to state whether they were using breast or bottle.
Overall, 137 of the infants were exclusively breastfed, 88 were exclusively bottle-fed, and 91 were fed with a mixture of formula and breast milk.
Breastfed babies were deemed to have “more challenging emperaments” and tended to cry more.
Rosie Dodds, of the National Childbirth Trust, said the new observations were useful for parents.
“Mothers and babies may experience starting to breastfeed as demanding or stressful in this society where bottle-feeding is seen as the norm and breastfeeding is unfamiliar to many new parents.
“It would be interesting to compare this with countries where almost all babies are breastfed.
“We often hear from mothers who say that once both they and their baby got the hang of it, breastfeeding was a breeze.”