The Long-Term Effects of Co-Sleeping with Children

In most societies around the world, children sleep with their parents at least for the first several years of their life. Early anthropological studies found that in 90 percent of cultures, infants slept with their parents, and not in cradles or cribs, according to anthropologist Emmy Elizabeth Warner. Co-sleeping is not limited to primitive cultures. A majority of Japanese children co-sleep with their parents through the early school years, and half co-sleep with their parents until the mid teens, according to multiple sources including Sleep and Breathing in Children. Western culture has long emphasized independence in sleeping arrangements, encouraging parents to have infants sleep in cribs or cradles, often in rooms of their own. Despite marked differences in attitudes in most Western cultures, about 26 percent of American children between the ages of 2 to 9 months always or almost always co-sleep with their parents, according to Natural Child.

Family co-sleeping. (Image: 8213erika/iStock/Getty Images)

Independence from Stronger Attachment

One implicit rationale for having babies and children sleep separately from their parents is to encourage greater independence in the child. Ironically, most research suggests that co-sleeping fosters greater independence and autonomy as children grow, according to Kids Internet Radio. The notion that earlier experiences affect later functioning is the sine qua non of psychological and development theory. Satisfaction of infants' and children's need for attachment, attention and human contact, such as occurs in co-sleeping, establishes greater confidence and esteem in children, according to Mother-Baby Behavioral Sleep Laboratory.

Physical Health Benefits

Children who co-sleep have better health in the short and long term, according to Kids Internet Radio. Anthropologist and sleep researcher James McKenna from Notre Dame offers several explanations for this finding. First, babies are calmed by the presence of their parents and therefore cry less. Babies who cry due to separation from their parents release more of the the stress hormone, cortisol, during their distress. Chronic exposure to cortisol adversely affects immune functioning. On the flip side, babies who sleep with their mothers are breastfed twice as often, according to Dr. McKenna, which boosts their immune system functioning.

Happier and Better Adjusted

Various studies described on Dr. McKenna's website, Mother-Baby Behavioral Sleep Lab, suggest that co-sleeping enhances mental health and well-being. A study of English school children found that children who never slept with their parents were more fearful than children who always slept with their parents. Similarly, English school children who slept alone were less adept at handling stress, were more difficult to handle and were less independent than children who slept with their parents. A multi-ethnic study of 1,400 adults found that those who co-slept as a child reported a greater satisfaction with life. Dr. McKenna notes that these correlational studies don't necessarily indicate these positive outcomes are direct effects of co-sleeping. Rather, co-sleeping is one component of a system of attachment and relationships that interact with the child's own qualities, which over the course of development contribute to adult characteristics.