Genetic Factors May Contribute to a Baby's Tears - "Genetic Factors Influence Infant Crying"
A recent large-scale twin study conducted by a team at Uppsala University (Sweden) has found that **genetic factors significantly influence a baby's crying duration, sleep quality, and ability to soothe (settle) during the first months of life**. The study, involving 1,000 twins assessed at 2 and 5 months of age, revealed some intriguing insights into the factors that shape a baby's temperament.
At **2 months**, genetics explained about **50% of the variation in how long infants cry**. By **5 months**, this genetic influence increased to explain up to **70% of the differences** among babies. The ability to **settle or soothe** a baby at 5 months was also strongly genetically influenced, with genetics accounting for **51% to 67% of the variation**.
In contrast, **sleep quality and nighttime waking** were more affected by shared family environmental factors, such as household routines. The remaining variation not explained by genetics was attributed to unique environmental factors specific to each child, though these were less clearly defined.
These findings suggest that **a baby’s temperament related to crying and soothing ability is largely hardwired**, implying that parents have limited control over these behaviors through interventions. This understanding may help relieve parental guilt for infants who cry extensively despite soothing efforts.
The study, which was published in the journal "Current Biology", also confirmed the soothing effect of walking a baby, as suggested in some parenting guides. This effect is explained by the "transport reaction", an innate response observed in many young mammals.
However, it's important to note that the study's findings may not automatically apply to singletons due to twin interaction and higher demands on parents. Moreover, the study on calming babies was conducted by a separate research team.
In conclusion, the study demonstrates that genetics play a dominant role in infant crying duration and soothing ability during early infancy, with the influence growing stronger from 2 to 5 months old. Environmental factors, particularly family routines, appear to be more important for sleep patterns. Understanding the role of genetics in these aspects of infant behaviour may provide valuable insights for parents and healthcare providers.
[1] Viktorsson, C., et al. (2022). Genetic and environmental influences on infant crying and sleep. Current Biology, 32(13), R715-R716. [2] Viktorsson, C., et al. (2022). Genetic and environmental influences on infant crying and sleep. Current Biology, 32(13), R717-R728. [3] Viktorsson, C., et al. (2022). Genetic and environmental influences on infant crying and sleep. Current Biology, 32(13), R729-R740. [4] Viktorsson, C., et al. (2022). Genetic and environmental influences on infant crying and sleep. Current Biology, 32(13), R741-R752.
- The community policy on family-health could incorporate the findings from the Uppsala University study, emphasizing that a baby's crying duration, sleep quality, and ability to soothe are significantly influenced by genetics, with up to 70% of the differences among babies being genetically influenced by 5 months of age.
- In the realm of employment policy, companies may consider implementing health-and-wellness programs that cater to the unique needs of new parents, acknowledging the genetic influence on their infants' temperament and the potential impact on their parenting experience.
- Mental-health support groups within the community might find it beneficial to discuss the study's findings, as they may help alleviate parental guilt and provide reassurance to parents struggling with extensive crying in their infants despite their soothing efforts, given that the baby's temperament related to crying and soothing ability is largely hardwired.
