Study on the Social Adaptation of Chinese Children with Down Syndrome

Most studies on the development of children with disabilities focus either on clinical findings or on mechanistic models of learning. With recent theoretical advances in the field of child development research, a broader view on the skills of children with inherited developmental retardation is needed. Studying atypical developmental patterns may contribute considerably to the understanding of human adaptive processes.

Down syndrome (DS), also known as trisomy 21, is the most common cause of inherited intellectual disability. The syndrome is clinically characterized by congenital malformations (especially of the heart and the gastrointestinal tract) which result in a high mortality early in life. As a result of many advancements in the medical treatment of individuals with DS, long-term survival has considerably improved. Estimates of life expectancy in Western countries suggest that about 44% of patients with DS reach the age of 60 and 14% reach the age of 68.1

Delayed development of cognitive capacity is a primary consequence of DS.2, 3 Study results show a slowed cognitive development over the first three years of life4-7 so that by early childhood most children with DS have standard cognitive performance scores at least two standard deviations below the mean reference scores. Their cognitive skills grow at a lower rate than that found in normally-developing children. Other results show a general decline in standard cognitive scores in the late adolescent period.8

Investigations on the emergence of other skills in specific areas of development have revealed typical patterns. Some researchers reported that children with DS appear to exhibit a particular weakness in communication, especially with respect to expressive (i.e., spoken) language.9-15 In contrast, social development and the mastery of adaptive skills associated with the tasks of daily living are far less affected.15, 16 However, development in these areas also takes place at a slower rate than in normally-developing children.

DS provides a unique opportunity to study a group of children with a type of developmental retardation that is etiologically distinct and homogeneous yet functionally heterogeneous.17, 18 In order to explore the potential for social adaptability and development in children with DS more systematically, DS patients should be studied in comparison with normal children matched for both mental age and chronological age. To our knowledge, no such studies have been reported on DS children of Chinese ethnicity. How do the typical profiles of cognitive retardation affect the social development of Chinese children with DS? Do the same patterns found in Western DS children exist in Chinese children with DS? The exploratory study presented here focuses on the question of whether an etiology-specific profile exists for social adaptation in Chinese DS using the Infants-Junior Middle School Students' Social-Life Abilities Scale.19

The aim of the present study was to gain more information about the social adjustment of children with Down syndrome in China. It is important to acknowledge the limitation of the assessment tools and the fact that there are no well-validated instruments for measuring cognitive development in Chinese children with DS. In Western countries, mental retardation is common in DS, with IQs typically in the range of mild (50-70) to moderate (35-50) retardation.21 In this study, the IQs of only three children could be measured using the WISC-R, and the highest score achieved was 47. PPVT was employed in this study as it has been used in previous studies on developmental disorders, and it seems more suitable than the WISC-R for testing children with DS. Even so, it was not possible to calculate an individual IQ and mental age in most DS patients because their chronological ages exceeded the age range of the test as the range was from three years six months to eight years six months. Therefore, the PPVT raw score had to be adopted as the measurement of verbal mental age in our study.

An increasing number of women in China choose caesarean section as a less painful mode of delivery, since most of women only have one baby due to the family planning policy. The quality of medical service at a hospital is considered very important in China, and in recent years a high rate of selective caesarean sections has occurred as it is widely accepted as a proper way to avoid injuries of the mother and the newborn during labor and delivery. In this study the caesarean birth rate was higher in the MA group than in the two other groups.

DS children are more susceptible to certain diseases than are normally-developing children, and these diseases include congenital heart disease, intestinal abnormalities and infectious diseases.22 DS children often have a history of postnatal illness, which can greatly contribute to the mental retardation.

Family structure plays an important role in the cognitive and social development of DS children. Since the implementation of the family planning policy in China, family characteristics have undergone great changes. In urban areas, most families are only-child nuclear families, except those who have handicapped children. In rural areas, most couples are permitted to have a second child, especially if the first is female. Yet with the progress of society, many couples who are permitted to have a second child choose to have only one child.23 The nuclear family with one child has become the mainstream of society. When a family has a baby or toddler, or has a handicapped child, grandparents usually are invited to live together with the young family, for economic reasons or as a matter of custom. As the child grows up, the grandparents return to live by themselves, while the MA group are still young, and the DS group are handicapped so the grandparents still live with them Therefore, the nuclear family with one child was the main social living environment for children in the CA group, but not in the DS or the MA groups. The handicapped child usually was the most important member and the center of the family. The practice of spoiling handicapped children may aggravate the retardation of social adjustment abilities because DS children have no chance to practice their skills.

In addition to family structure, the educational level of the parents also plays an important role in the development of social adaptation.24-26 Compared to typically-developing children, the educational level of parents with DS children was significantly lower in our study. In the more prosperous areas of China, prenatal screening has become more popular for well-off parents. To some degree, parents with a low educational level are less likely to participate in routine examinations during pregnancy, so that in this case pregnant women miss the chance of prenatal diagnosis of many genetic diseases. After the birth of a DS child, well-educated parents may provide a better environment for the growth and development of their disabled child and, for example, may more readily participate in early intervention programs. Early intervention can help many children with DS to develop their full cognitive and social potential and live productive lives well into adulthood.27-29

The term "behavioral phenotype" may best be described as "the heightened probability that people with a given syndrome will exhibit certain behavioral and developmental sequelae".30 The results of our study suggest that a differentiated view on cognitive and adaptive development is needed in DS patients, who in this respect differ from what is seen in children with Williams syndrome. Compared to the MA group with a chronological age of around three years, DS children on average scored higher on the Infants-Junior Middle School Students' Social-Life Abilities Scales, at a level that is equivalent to what is expected from normal, four-year-old children. Thus, although the PPVT raw scores in the DS group showed no differences when compared with the MA group, the ability to utilize skills within a general social context tended to be better in DS children. This pattern of results is consistent with the idea that the diagnosis of mental retardation does not define the person: individuals with DS can continue to learn throughout their lives.

While rarely used in China, the Vineland Adaptive Behavior Scales (VABS) have been widely employed in the investigation of developmental retardation in Western countries.31-33 The VABS measures adaptive behavior in four domains: communication, daily living skills, socialization, and motor skills. It is difficult to directly compare the results of DS children from Western countries and from China because of the different test instruments used. However, it seems that a particular weakness in communication is seen in both Western and Chinese DS children, while the mastery of adaptive skills associated with the tasks of daily living is far less affected.16, 33 Children with DS often are noted to have speech delays. Understanding or receptive language is often better than speaking or expressive language.34-36 Poor muscle tone in the oral structures can lead to hypernasality, imprecise consonants, breathiness, a harsh voice, and short phrases, which can make speech difficult to understand.37 These all greatly contribute to the delay of communication. Because most DS children in Western countries, but not in China, are subject to early intervention after birth, they should show better social adaptability than Chinese DS children. The low levels of cognition and social competence found in this study suggest that families with DS children in China need appropriate professional help to promote the cognitive and social development of their children as early as possible.

Children in the CA group got higher scores than DS patients in all dimensions of social adjustment. This is in agreement with the idea that the development of cognition is associated with the development of social adjustment and quality of life.38, 39 Motor development, language and executive functions are all engaged in the development of social adjustment. To a certain extent, cognition predicts the individual potential and the characteristics of social adaptation, while training and education are often considered to have less of an impact on children with developmental retardation, and therefore they are then more likely to be withheld.40

In this study, the development of adaptive behavior was significantly correlated with the development of cognition, even after controlling for age. At the same time, age-related cognitive development was significantly correlated with social adaptive ability, too. An earlier study reported significant age-related developmental progress in adaptive functioning in children with DS from infancy to elementary-school age, whereas in middle school a stagnation of social adjustment was documented.16 Chinese DS children usually enter elementary school from the ages of 8 to 11. Most of them have had no intervention before that time. Learning in special schools provides sufficient opportunities to develop the children's potential so that social adjustment in DS children of school age should develop continuously. Further investigations are needed that address a possible stagnation of development among Chinese DS children in middle school.

Children with DS require special health care and early interventions to ensure optimal development, which also has a significant impact on their family. Independence training for the affected individuals and advice to their parents for effective intervention might result in adults with DS becoming less dependent on their families for support and more able to utilize those skills and abilities that they undoubtedly possess.