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COLCHESTER, United Kingdom — Parents often wonder what long-term impact their early parenting decisions will have. One common practice that has sparked debate is co-sleeping – when parents and toddlers sleep in the same bed. While some believe this strengthens the parent-child bond, others worry it could lead to sleep problems or other issues. A new study published in the journal Attachment and human development sheds light on this issue and suggests that co-sleeping at nine months of age has no impact on a child’s emotional and behavioral development in later childhood.
The study, led by researchers at the University of Essex and other British institutions, used data from the Millennium Cohort Study, a large-scale project that tracks the lives of children born in the UK between 2000 and 2002. The researchers examined information from 16,599 children, tracking their development from infancy to age 11.
The main aim was to find out whether co-sleeping at nine months of age is associated with different patterns of internalising and externalising symptoms in later life. Internalising symptoms refer to emotional problems such as anxiety and depression, while externalising symptoms include behavioural problems such as aggression or hyperactivity.
To understand how these symptoms developed over time, the researchers used a sophisticated statistical method called Parallel Process Latent Class Growth Analysis. This approach allowed them to identify distinct groups of children who showed similar patterns of emotional and behavioral development between the ages of three and 11.
The analysis revealed four main groups of children:
- Low stable (56.5%): Children with consistently low scores on both internalizing and externalizing symptoms.
- Small increase in internalizing, moderate decrease in externalizing (27.2%): Children whose emotional problems increased slightly over time while behavioral problems decreased.
- Moderately decreasing (7.5%): Children who had moderate levels of both symptom types at baseline that decreased over time.
- Low increasing internalizing, high stable externalizing (8.9%): Children whose emotional problems increased from a low starting point while behavioral problems remained consistently high.
First, the researchers found that children who bed-shared at nine months were slightly more likely to be in one of the groups with higher levels of symptoms. But this association disappeared when they took into account other factors that might affect a child’s development. These factors included things like the mother’s mental health, the child’s temperament, and family characteristics such as single parenthood or ethnicity.
This finding suggests that co-sleeping itself does not cause emotional or behavioral problems, but rather that other aspects of a child’s environment and family life have a greater impact on their development.
The study’s findings offer reassurance to parents who choose to co-sleep in bed. They suggest that this practice, when implemented at nine months of age, does not have long-term negative effects on a child’s emotional and behavioral development. However, the researchers note that their study does not address the safety aspects of co-sleeping in bed with younger infants, which remains a separate issue.
Dr. Ayten Bilgin, the lead author of the study, stresses that parents should be informed that co-sleeping during the second half of the first year is unlikely to have any impact on their child’s later emotional and behavioral development. This information can help parents make decisions based on their own circumstances and preferences without worrying about possible long-term consequences.
“Despite the ongoing debate about the potential long-term harms and benefits of co-sleeping, little scientific research has been done on this topic,” Bilgin said in a statement. “Parents can be assured that co-sleeping, as long as it is practiced safely, is unlikely to have negative effects on children’s emotional and behavioral development. There is a lot of guilt and shame associated with co-sleeping – but it is a parental choice.”
The study’s findings challenge some previously held beliefs about the benefits or risks of co-sleeping. While some proponents of co-sleeping argue that it promotes emotional security and better self-regulation in children, this large-scale study found no evidence to support these claims. On the other hand, no negative effects were found either, contradicting concerns that co-sleeping could lead to more behavioral problems.
It’s important to note that the study focused on bed-sharing at a specific age (9 months) and looked at the results over a specific period of time (ages 3 to 11). The researchers acknowledge that the effects of bed-sharing may be different if it occurs at other ages or continues for a longer period of time.
This study serves as a reminder that there is no one-size-fits-all approach to parenting. The lack of significant long-term effects of co-sleeping at nine months underscores the importance of parents trusting their instincts and choosing the approach that works best for their family. While safety concerns remain critical with younger infants, this study offers reassurance to parents who choose to co-sleep with older infants, as they can prioritize immediate family harmony without worrying about future consequences.
Summary of the paper
methodology
The researchers used data from the Millennium Cohort Study, a large-scale study that followed thousands of children born in the UK. They looked at whether these children shared a bed with their parents at 9 months of age and then tracked their emotional and behavioural development at ages 3, 5, 7 and 11.
To assess emotional and behavioral problems, they used the Strengths and Difficulties Questionnaire (SDQ), which was completed by parents. This questionnaire asks about various aspects of children’s behavior, such as anxiety, aggressiveness, and attention span. The researchers then used a sophisticated statistical technique called Parallel Process Latent Class Growth Analysis to group the children based on how their emotional and behavioral symptoms evolved over time. They also took into account various factors that could influence a child’s development, including family background and the mother’s mental health.
Key findings
The study identified four main groups of children with different patterns of emotional and behavioral development. The majority of children (56.5%) had consistently low levels of problems throughout childhood. Approximately 27% showed increasing emotional problems but decreasing behavioral problems. A small group (7.5%) began with moderate problems that decreased over time, while another small group (8.9%) had increasing emotional problems and persistently high behavioral problems.
Initially, co-sleeping seemed to be associated with belonging to the groups with the most problems. However, this association disappeared when the researchers took into account other factors, such as family situation and the mother’s mental health. This suggests that co-sleeping itself is not a causal factor for these problems.
Limitations of the study
The study only examined bed-sharing at 9 months of age, not earlier or later periods. All data were collected through parent report, which may introduce bias. The researchers were unable to distinguish between families who chose bed-sharing and those who did so out of necessity, such as to resolve sleep problems. In addition, the study did not consider the duration of bed-sharing beyond 9 months. These limitations highlight the need for further research to fully understand the complex relationship between bed-sharing and child development.
Discussion & Insights
The main conclusion of this study is that bed-sharing at 9 months of age does not appear to significantly affect a child’s emotional and behavioral development in later childhood. This finding refutes both positive and negative claims about the long-term effects of bed-sharing. The research suggests that other aspects of a child’s life, such as family circumstances and parenting style, play a more critical role in shaping their development than whether they shared a bed as an infant.
These findings may help parents make informed decisions about sleeping arrangements without undue concern about long-term consequences. However, the researchers stress that this study does not address safety concerns associated with bed sharing with younger infants, which remains an important, separate issue.
Financing and Disclosures
The researchers stated that this particular study received no special funding. They used data from the Millennium Cohort Study, which is funded by the Economic and Social Research Council and a consortium of UK government departments. In their disclosures, the authors stated that there are no conflicts of interest related to this research, ensuring transparent reporting of their findings.
