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pISSN 2093-9175 / eISSN 2233-8853 REVIEW ARTICLE Med Res 2014;5(2):37-42

Cultural Issues of Co-Sleeping in Korea

Seockhoon Chung, MD, PhD, Hoyoung An, MD Department of Psychiatry, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea

Co-sleeping is a natural part of in the Eastern culture; however, it may seem strange and possibly even dangerous to Western cultures. In the West, parental age, race, marital status, and house income may influence co-sleeping, while co-sleeping, especially - sharing, is usually considered to increase the risk of sudden infant death syndrome. In Korea, however, people usually believe that a baby must not sleep alone in an empty room. The differences in the prevalence of co-sleeping between Eastern and Western society may be rooted in differences in -care philosophies, sleeping habits, and home architecture. In this article, the hazards and benefits of bed- sharing will be reviewed, and differences in co-sleeping will be addressed from a cultural viewpoint. Sleep Med Res 2014;5(2):37-42

Key WordsaaCo-sleeping, Cultural diversity, Sudden infant death, Parenting.

INTRODUCTION

In Eastern cultures, co-sleeping is a natural part of parenting.1-3 This may seem strange and possibly even dangerous to Western cultures, but studies have shown that it is also relatively common even in the West, albeit only among African Americans, Hispanics, and Asians.4 The same study also reported that the proportion of bed sharing as a usual practice actually increased in the US from 5.5% to 12.8% between 1993 and 2000. Thus, co-sleeping may be more wide- spread than previously thought. The factors that predispose to share a room or bed with their children during the night are different between cultures, and reflect differences in child-care philosophies, sleeping habits, and home architecture. In the West, factors such as parental age, race, marital status, and income are known to influence co-sleeping, with younger mothers, single mothers, African American or Asian mothers, and with lower income being more likely to sleep in the same room or bed with their children.4,5 Families with very young babies also tend to practice co- sleeping. In contrast, in the east, co-sleeping was found to be influenced not only by parental and child age, but also by factors such as maternal attitudes towards co-sleeping, and number of children, with younger parents, parents with positive attitudes towards co-sleeping, and parents with a small number of children being more likely to practice co-sleeping.1,2 Poor child health was also associated with an increased incidence of co-sleeping. Received: October 11, 2014 6 Revised: October 28, 2014 Co-sleeping was likely the rule in ancient times. Environmental factors such as low nighttime Accepted: November 3, 2014 temperatures or rain, and the presence of predators, poisonous bugs, insects, and possibly even Correspondence other humans likely made it near impossible for parents to leave their children alone during the Seockhoon Chung, MD, PhD Department of Psychiatry, night. Sleeping with a child was a means to increase the probability of his or her survival. Breast- Asan Medical Center, feeding may also have been another factor.7 As times changed, however, humans learned to University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, build houses and divide them into rooms so their offspring would be safe during the night. Songpa-gu, Seoul 138-736, Korea Changes in society have been accompanied by changes in the attitude towards co-sleeping. Tel +82-2-3010-3411 Fax +82-2-485-8381 Rather than being a vital method of child protection, it has become a matter of choice for par- E-mail [email protected] ents. With this change, several issues emerged which sparked intense controversy over the haz-

Copyright © 2014 The Korean Society of 37 Cultural Issues of Co-Sleeping ards and benefits, the most important being the recognition of There have also been several studies investigating bed-sharing Sudden Infant Death Syndrome (SIDS). Much research has been in breast-feeding infants. As any mother who has breastfed their conducted to elucidate its etiology and risk factors, and it is now child can attest, bed-sharing greatly facilitates breast-feeding.6,14,15 understood to be associated with mother-child bed-sharing.8 This finding has led to studies comparing bed-sharing between These findings prompted the American Academy of breast-fed and formula-fed infants, with several reports focusing to issue guidelines warning against bed-sharing, but not room- on differences in sleep position.7,15 Whereas formula-fed infants sharing.8 In the next section, the hazards and benefits of bed- were more likely to sleep on their backs and at the level of their sharing will be reviewed, and the differences in co-sleeping will mother’s nose or chin, breast-fed infants were more likely to be addressed from a cultural viewpoint. sleep laterally, at the level of their mother’s chest. The difference in sleep level observed was constituted by whether or not the in- fant was in contact with a , which is a well-known risk fac- BENEFIT AND DANGEROUSNESS tor for SIDS.8 Breast-fed infants were less likely to sleep on a pil- OF BED-SHARING low, and were thus comparatively safer from SIDS. Although the lateral position of the breast-fed infants seemed to be risky at When the issue of co-sleeping first arose, the distinction be- first, researchers found that the infants usually did not have tween room-sharing and bed-sharing was not clearly defined, enough space to roll into a prone position due to proximity of and studies tended to use the term ‘co-sleeping’ interchangeably the mother’s body. Other studies analyzed to refer to both. However, further investigation started to uncov- findings from mother-infants pairs who were either bed-sharing er the difference between sharing a bed and sharing a room, and or sleeping solitarily.11,16 The authors reported that bed-sharing the terms ‘bed-sharing’ and ‘room-sharing’ are now used instead promoted infant arousals, arguing that this may act as a protec- of the more inclusive ‘co-sleeping’.8 In this article, the terms ‘bed- tive factor for SIDS. sharing’ and ‘room-sharing’ will be used when possible, and ‘co- Another controversial finding from bed-sharing studies con- sleeping’ will be used as an umbrella term which includes both. cerns the increased levels of CO2 around the infant, within the The benefits of bed-sharing may include increased arousals in so called ‘air-pocket’.7 Researchers used a doll equipped with a the infant and mother, facilitation of breast-feeding, and im- measurement device to analyze the CO2 concentrations from 3 proved -child relationships, while the hazards may include to 21 cm from the mothers’ nares. They concluded that although increased risk for SIDS, marital discord, and inhibition of inde- the levels were increased compared to room air, they were not pendence in the child. However, this categorization is under high enough to be lethal. In fact, based on past studies, the levels much debate, as the effects and implications of each factor are were within the range that has been shown to naturally stimulate not clear, as shall be discussed below. respiration and promote normal breathing. Bed-sharing has repeatedly been implicated as a risk factor for Studies on bed-sharing have also reported increased arousals SIDS,6,8-10 compelling the American Academy of Pediatrics to of- of the mother. Several researchers investigating sleep parameters ficially discourage its practice.8 Although the relationship be- in mothers sharing beds with infants showed increased arousals tween bed-sharing and SIDS has not been proven conclusively, or arousal behavior in the mother, frequently associated with epidemiological studies have demonstrated a clear association breast-feeding.7,12,15,16 One study reported reduced duration of between the two. Furthermore, reports concerning poor sleep in slow wave sleep, with a reciprocal increase in stage 1–2 sleep, but bed-sharing infants have argued that bed-sharing may have oth- no change in , total sleep time or dura- er negative effects.1,5 However, recent studies focusing on the tion of waking after .12 Although this may not be ben- context in which bed-sharing is practiced have shown that the eficial for the mother, from the infant’s perspective, increased same conclusions may not be applicable in every case. arousals would permit the mother to look after and care for the One of the most replicated findings of sleep studies compar- infant more vigilantly. However, long-term effects on the moth- ing solitary-sleepers and co-sleepers is the increased frequency er, and consequently, on the infant, have not yet been clearly as- of awakenings during the night.11 However, while the finding it- sessed. In addition, one study concluded that increased infant self is simple, the implications have caused much controversy. In night waking may contribute to depressive symptoms in the adults, frequent waking during the night is a sign of poor sleep, mother.17 which may also hold true for young children. Conversely, some Based on these reports, it may be argued that co-sleeping on researchers have argued that increased awakening may increase the whole, and possibly even bed-sharing, cannot be seen simply arousal, and help the infant wake up during episodes of breath- as a risky practice that must be avoided in all situations. It seems ing difficulty.12 In this light, increased arousal from bed-sharing that the risks of bed-sharing may differ according to the sur- could be seen as a protective factor. However, other studies have rounding context or situation. As discussed below, cultural dif- suggested that these findings may be the results of report bias.13 ferences may also a role. No studies have yet been able to clear up this matter.

38 Sleep Med Res 2014;5(2):37-42 Chung S and An H

CULTURAL DIFFERENCES IN Despite being geographically and historically close to Korea, CO-SLEEPING STYLE the of Japan and China show several key differences. Each has a unique heating system and arrangement. In Japan, a device called Irori27 was used for heating. It was a fire- Physical Differences in Bedroom Design place set up in the middle of the room, used to heat the air. As The “bed” and the “carpet” are the most prominent differences with Western fireplaces, it was unable to heat the floor, so a Tata- in room décor between Western and Korean traditional bed- mi,28 which is a traditional Japanese mat made from rice straw or rooms. Beds have been used since ancient times in Western cul- woodchips, was used to cover it. Beds were not used, and people ture. One of the reasons for this is the carpet. Western homes slept on the floor. Nowadays, the Irori is still in use (in a mod- typically used a fire-place or stove for heating, which is effective ernized form, called a Kotatsu29), but instead of Tatami mats, at heating the air. However, it is unable to heat the floor, and beds have gained widespread use. thus, the carpet was developed as a countermeasure. While cold In China, beds have been used for centuries. However, the floors can take away body heat very rapidly, this effect can be structure of the traditional bed was very different from that of offset by the carpet, making walking or sitting on the floor much Western ones. Instead of having separate heating and more comfortable. However, the carpet can also be a reservoir systems, the two were combined into a bed-stove, or Kang.30,31 A for biological contaminants, such as dust mites, dust mite aller- typical Chinese Kang consists of a stove, a Kang body (similar to gens, and molds, which can impair physical health.18,19 Further- a bed) and a chimney. Hot air and smoke from the stove heated more, people in Western cultures usually wear shoes at home, the kang, and the kang heated the air around it. This system is which may aggravate the deleterious effects. Sleeping on a bed still used in some rural areas, but urbanites are more likely to use can help protect the inhabitants against these effects while also modern boilers and radiators to heat their homes, while sleeping improving the sleeping environment, and thus it gained wide- on beds.32 spread use. Although fireplaces are no longer very common, the Compared to the West, room-and bed-sharing is compara- heating systems that have taken their place, for example, radia- tively more prevalent in all three countries, despite the differenc- tors and forced air furnaces, are based on the same principles, es in bedroom design mentioned above.1-3 The reasons for this and are thus focused on heating the air.20 are not clear, although parenting methods may play a role. The traditional Korean bedroom is built and arranged some- what differently. The main difference may be found in the heat- Parenting ing system, which is called ‘O n d o l ,’ 21 or warm-stone. In the tradi- Compared to the individualism of the West, Koreans are cul- tional setting, houses were built to have a hollow space under the turally collectivistic. The virtue of filial piety runs deep, which floor in which a set of large stone blocks were arranged. The hol- includes influences from Confucianism, Taoism and Mahayana low space was part of the exhaust system, with one side opening Buddhism, and ‘’ holds a unique psychological position in into the Buddumak (kitchen range or stove) or Agungii (fire fur- the minds of most people.33 Collective needs, interdependency nace), and the other side into the chimney. Hence, hot air and and conformity are emphasized, while protection and obedience gases from cooking fires passed through the Ondol and heated are taught as core values. During parenthood, elimination of risk the floor before being released. The stones increased heat trans- and providing support are usually given priority. Immense devo- fer and efficiency.22 Thus, domestic life was centered around the tion and sacrifice are expected from parents while providing for warm floor, on which people ate, rested, and slept, and there was their children, and these principles are usually highly involved no need for the development of complex and expensive carpets throughout their children’s lives.34 In practice, children are al- and beds. In terms of sleeping arrangements, this difference most always accompanied by an adult, as can be seen from the made a big change. Bed-sharing and room-sharing was compar- ‘Podaegi’, a Korean traditional hands-free baby carrier. While atively much easier since the whole floor, instead of just the bed, using it, women were able to carry their young while working. could be used for sleeping. Various infant health and safety is- Furthermore, college tuition and costs are usually cov- sues, such as dirty carpets, risk of falling from the bed,23 risk of ered by parents, and many parents continue to provide some suffocation,24 or strangulation25 could therefore be avoided. Fur- sort of economic support until their offspring are in their late thermore, parents did not need to worry about crib-related acci- 20s. Within this atmosphere, co-sleeping is considered natural, dents, as cribs were not needed.26 The ondol system is still used and possibly even an obligation.2 Parent-child co-sleeping is a today, although hot water pipes are employed instead of stones method of caring for the child, even while the child is sleeping, and Buddumaks.22 The floor is still warm, so although beds are and solitary sleeping is considered to be a form of neglect. While now in wide use, a large number of mothers opt to sleep on the the number of bed-sharing parents has decreased with the floor with their newborns after birth. This bed-sharing/room- spread of Western culture and increased public awareness of sharing arrangement may go on for several years, sometimes SIDS, most parents are still present when the child falls asleep.35 well into elementary school. In Western-style parenting, encouraging the independence of

www.sleepmedres.org 39 Cultural Issues of Co-Sleeping a child is considered an important aspect. Priorities are given to Attitudes toward Co-Sleeping autonomy, infant separation and emotional independence. This Attitudes towards co-sleeping are another important factor in gave rise to ‘babywise parenting’, in which establishing a routine determining whether or not parents actually practice bed-shar- and teaching discipline are given importance for successful par- ing and/or room-sharing. From this perspective, the two main enting.36 Anthropologists argue that this may be one of the rea- considerations are the quality of parental sleep and marital inti- sons why co-sleeping is comparatively rare in the postindustrial macy. Some studies have reported that parental satisfaction con- West.7 Conforming to social values and following ‘expert’ advice, cerning sleeping arrangements and marital intimacy did not dif- parents were taught that teaching a child to sleep alone and fer between solitary sleepers and early bed-sharers (e.g., infants sooth him or herself when needed was an important part of who started to sleep with their parents before one year of age), childcare. with most parents answering ‘satisfied’ or higher upon evalua- Proponents of infant separation and independence consider tion.40 Another study based on children with sleeping problems autonomy-granting as a key variable in their theory, situating it reported that co-sleeping was associated with higher levels of on a spectrum with encouragement of independence and over- marital distress.41 The parents in the first study were probably protection on each end.37 These results are under much contro- able to choose whether or not to sleep together, which may have versy, as are the conclusions of other studies on parenting, as helped them accept the situation and adapt to it comparatively there is little consensus to how these dimensions should be con- easily. On the other hand, the parents of the latter study may structed. Some researchers place psychological control on the have been forced into doing so due to the sleeping problems of opposite end as independence, yet overprotection and psycho- their child. Thus, the adaptation process would have been more logical control are very different values. Furthermore, when di- difficult. These findings indicate that parental attitudes can be mensions are constructed as spectrums (e.g., autonomy-granting influenced by the reasons for co-sleeping, which in turn affect on one extreme and psychological control on the other), the in- parental satisfaction. crease of one construct usually indicates a decrease or absence of As mentioned above, Koreans are traditionally collectivistic, the other. However, parents may not necessarily belong in either traces of which can even be seen in the spoken language. For in- group. This field is further complicated by cultural differences, stance, instead of using “me” or “my”, the term “Wuri” (which means thus empirical validation of the constructs will be needed before “we” or “our”) is used in phrases such as “our husband” or “our any dimensions can be applied to other cultures. wife”, which may seem inappropriate to Westerners. In Korea, rather than considering oneself as an individual, people consider Is Sleep Really That Important?-Acceptance of themselves as part of a ‘whole’, which in many cases is an indi- Co-Sleeping vidual’s family. Thus, the needs and wants of the family as a The culturally perceived importance of sleep may also play a whole are given more priority over those of an individual com- role in co-sleeping. Eastern societies are well known for their pared to the situation in Western families. As sleep quality and ‘sleep less, work more’ ethic, and studies have shown that East- marital intimacy, including sex life, are individual values, they erners may sleep up to an hour less than the people in some are given low priority in comparison to caring for the baby, mak- Western societies.38 This difference is even greater in high school ing parents more likely to sacrifice them in order to care for the students.39 The college entrance exams of Japan and Korea are baby at night. In addition, as grown adults are also expected to notorious for their competitiveness, causing great pressure to re- care for their elders, extended families are not uncommon. In duce sleep for increasing study time. This leads to radical reduc- this situation, room shortages may also increase the likelihood tion of the sleep time, with an average sleep duration of just 5 of co-sleeping.2 hours and 27 minutes. Consequently, sleep is naturally given What parents actually think of bed- or room-sharing is also comparatively less weight compared to in Western countries. important. It is interesting to note that there is no word for bed- This is also reflected in indoor lighting. Whereas Western homes sharing, room-sharing, or co-sleeping in Korean. This may be use dimmer lighting with indirect illumination, perhaps to allow because Koreans consider mother-infant co-sleeping as a natural better relaxation, Korean homes use direct illumination, and are thing, and possibly as an obligation. Many mothers reported that much brighter. Hence, it may be argued that people of Eastern they felt more comfortable when their children slept with them.2 countries, and Koreans in particular, are more tolerant towards Koreans also believe that such a habit is ‘good for the child’s sleep disturbances. This may enable them to accept the antici- emotional stability’ and promotes ‘ among the family’. When pated decrease in sleep quality more easily. Therefore, although asked about the optimal duration of co-sleeping, Korean moth- sleeping with their children during the night may disturb par- ers usually gave the answer of between 3 to 6 years after birth,2,42 ents’ sleep, Korean parents easily accept the sacrifice of sleep to which is similar to the answers given by Chinese mothers.43,44 look after their children, even during the night. Low Rates of SIDS in Asian Culture The findings discussed above show that attitudes towards bed-

40 Sleep Med Res 2014;5(2):37-42 Chung S and An H sharing are generally more favorable in Eastern cultures, where be seen. it is also more popular. Then, since bed-sharing is a risk factor In the past, the term ‘co-sleeping’ was limited to describe bed- for SIDS,8-10 it could be expected that the rates of SIDS should sharing, for which the message concerning it may have been also be high in Eastern cultures. However, several studies have correct. However, the recommendations have changed. Co- reported that this is not so. In fact, contrary to expectations, the sleeping without bed-sharing is now recommended.8 In Korea, rate of SIDS in Asian cultures was found to be lower than in co-sleeping itself already indicates co-sleeping without bed-shar- most other cultures,8,45,46 causing much speculation. Of course, ing, as parents typically sleep with their children on the floor, not the possibility that infant deaths were not fully reported in Asian on beds. Therefore, the sleeping arrangement that has been countries should also be considered. Meanwhile, the sleeping ar- commonly used by Korean parents may be optimal, and parents rangements and practices of Asian parents have also received at- may be encouraged to conform to such an arrangement in the tention. A study comparing Eastern and Western parents con- future. cluded that Eastern practices were safer in terms of the major Conflicts of Interest risk factors for SIDS, despite the higher frequency of bed-shar- ing.46 Based on recent studies, bed-sharing in itself may be The authors have no financial conflicts of interest. viewed in a new light. A study comparing SIDS infants with REFERENCES controls reported that a large number of the deaths were discov- 47 1. Liu X, Liu L, Wang R. Bed sharing, sleep habits, and sleep problems ered approximately 90 minutes after usual waking time. This among Chinese school-aged children. 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