If you’re a new parent who, in a more or less sleep deprived state, googles this question, then the answer might put your mind at ease.
Many Google results will refer you to an old study that concludes that infant crying normally peaks around six weeks of age, after which it decreases markedly and stabilizes at a low level after three months.
Commonly referred to as the “crying curve,” parents can expect their babies to cry dramatically less after the initial peak. However, a new Danish study challenges this ‘cry curve’ model, by pooling data from parents from 17 different countries.
“We created two mathematical models that reasonably represent the available data. Neither of them shows that crying duration decreases so markedly after five weeks, which is otherwise observed in the graphs shown to parents. The available data shows that the crying is still part of many infants’ repertoire after six months,” says Christine Parsons, associate professor in the Department of Clinical Medicine at Aarhus University.
Widely used cry curve
The researchers behind the study compiled data from 57 research papers from around the world, in which parents recorded how much their babies cry each day.
The normal crying pattern, the “crying curve” that parents are often referred to today, is based on a 1962 US study, which focuses only on the first twelve weeks of a child’s life.
“This is a graphic that is often presented to new parents. If you google ‘crying baby’ you will see many images of this particular graphic. Therefore, we thought it would be interesting to model all the available data to see what type of best represents the data, and test if this is consistent with the original ‘cry curve’,” says Arnault-Quentin Vermillet, the paper’s first author.
Important tool for clinicians
Crying is one of the first forms of communication infants use to get their parents’ attention. Infant cognitive and emotional development is stimulated when parents respond appropriately to infant cues.
New parents often turn to the health care system for help if they are concerned that their child is crying too much.
According to Christine Parsons, it is therefore important that healthcare professionals and parents have a correct and accurate understanding of normal crying patterns in infants.
“For clinicians in particular, this is important because their job is to help, support and reconcile the expectations of any concerned parent. It is important that clinicians have up-to-date data on what is normal for infant crying, so they can be more supportive When parents perceive their child to be crying excessively, it can be associated with negative consequences for both parent and child,” she explains.
Patterns of crying vary a lot
A widely used definition for excessive crying, or colic, is when a baby cries for more than 3 hours a day, more than 3 days in a week. During the first 6 weeks after birth, colic is estimated to affect between 17 and 25% of infants.
Researchers at Aarhus University have developed two new models for the infant crying model. One of them shows peaks in infant crying after four weeks. The other shows that infants cry a lot and at a steady level for the first few weeks, after which the level drops.
However, neither pattern shows a steep decline, as it otherwise appears to do from the “original cry pattern”.
Another remarkable finding from the study is the difference in crying patterns among babies, both within and outside national borders, according to Christine Parsons.
As an example, she mentions that the limited data available indicates that children from non-Western countries such as India, Mexico and South Korea cry less than children from English-speaking countries such as the United States, Great Britain. Britain and Canada.