Nature v. Nurture in the Lifespan Development of People with Down Syndrome

mathias-sager-intelligence down syndrome human development

In this article, passive and active genotype -> environment effects in general and related to the cognitive development of people with Down syndrome (DS) are discussed. An emphasis is put on the high variability in profiles of DS, as well as on the existence of multiple intelligences such as musical, spatial, interpersonal, and naturalist abilities, although these are not included in traditional IQ tests that measure mainly linguistic and logical-mathematical abilities only. Also, intelligence is not fixed, it, however, defines a certain reaction range of possibilities. Neural plasticity, children’s universal desire to learn, and the importance of early guided participation of parents make clear that human beings are also the result of how they were brought up. In conclusion, it is less about nature VERSUS nurture than about nature AND nurture in human development. 

Down syndrome (DS) is a genetic issue caused by an additional copy of the 21st chromosome [1] and is a neurocognitive and behavioral development disability that includes verbal and attention deficits [2]. Individuals with DS suffer from medical problems such as heart disorders and visual deficiencies [3]. Around one in 700 newborns is affected by the DS [4]. Tobacco consuming [6], obese [5], and older women bear a greater risk [6]. Diagnosis in early pregnancy and, for example, fetal biochemical and functional stimulation therapy is assumed to lead to an improved development of the child’s DS phenotype [7]. Current average life expectancy of people with DS is between 55 and 60 years, and Alzheimer disease is common development [8].

Parents influence their children’s genes in a twofold way, through direct heritage and the expression of their own genes. With decreasing dependency on the parents, individuals are more actively seeking environmental influences by their own that fit their genetic abilities [1]. Babies’ cognitive development starts with a sensorimotor stage according to Piaget’s theory, in which they respond with movement to stimuli of objects such as the sight of the face of a parent [9]. Young children’s behavior with DS in therapeutic sessions may look quite normal. Indeed, evidence shows that the difference in the development of motor skills for individuals with DS lies in its delay rather than its characteristic [10]. The most aggravating deficits over time from early childhood to school age and beyond are verbal weaknesses [2], while the social behavior of persons with DS can be extraordinarily bright [1].

There is a big variation in profiles of DS. More specifically, the mental retardation may be different across cognitive domains; for example, due to DS, children’s verbal working memory is comparatively less capable than the visual-spatial memory [11]. Standard intelligence tests predominantly measure abilities related to language and logical-mathematical thinking and are neglecting areas like musical and spatial capacities that are, according to Gardner and his multiple intelligence theory, part of a wider human spectrum of intelligence [12]. [1] is pointing to a so called ‘reaction range’ for intelligence that represents the possible variation of cognitive development. For mild cognitive disabilities, as defined to be represented by IQ scores of under 70 [1], ‘normality’ may be well within reach. The plasticity of neural and muscle tissues can be harnessed by therapeutic measures [13].  Children’s active desire to learn [9] can be used by a supportive social process of guided participation [1]. It is important to remember (especially in developed western societies) that traditional IQ tests have little to do with achievement other than in the academic space [14]. IQ and cognitive development is “a reflection of how we are brought up” [15].

 

References

[1] Arnett, J. J. (2012). Human development: A cultural approach. Upper Saddle River, NJ: Pearson Education, Inc.

[2] Grieco, J., Pulsifer, M., Seligsohn, K., Skotko, B., & Schwartz, A. (2015). Down syndrome: Cognitive and behavioral functioning across the lifespan. American Journal Of Medical Genetics Part C-Seminars In Medical Genetics, 169(2), 135-149.

[3] Buzunáriz Martínez, N., & Martínez García, M. (2008). Psychomotor development in children with Down syndrome and physiotherapy in early intervention. International Medical Review On Down Syndrome, 12(2), 28. doi:10.1016/S2171-9748(08)70037-0

[4] Gardiner, K. J. (2010). Review: Molecular basis of pharmacotherapies for cognition in Down syndrome. Trends In Pharmacological Sciences, 3166-73. doi:10.1016/j.tips.2009.10.010

[5] Maternal obesity and risk of Down syndrome in the offspring. (2014). Prenatal Diagnosis, (4), 310. doi:10.1002/pd.4294

[6] Ghosh, S., Hong, C., Feingold, E., Ghosh, P., Ghosh, P., Bhaumik, P., & Dey, S. K. (2011). Epidemiology of Down Syndrome: New Insight Into the Multidimensional Interactions Among Genetic and Environmental Risk Factors in the Oocyte. American Journal Of Epidemiology, 174(9), 1009-1016. doi:aje/kwr240

[7] Baggot, P. J., & Baggot, R. M. (2017). Fetal Therapy for Down Syndrome: Report of Three Cases and a Review of the Literature. Issues In Law & Medicine, 32(1), 31-41.

[8] Hartley, D., Blumenthal, T., Carrillo, M., DiPaolo, G., Esralew, L., Gardiner, K., & … Wisniewski, T. (2015). Perspective: Down syndrome and Alzheimer’s disease: Common pathways, common goals. Alzheimer’s & Dementia: The Journal Of The Alzheimer’s Association, 11700-709. doi:10.1016/j.jalz.2014.10.007

[9] DeWolfe, T. E. (2016). Jean Piaget’s theory of cognitive development. Salem Press Encyclopedia Of Health,

[10] Sacks B., & Buckley S. (2003). Motor development for individuals with Down syndrome—An overview. Down Syndrome Education Online. Retrieved from http://www.down-syndrome.org/information/motor/overview/

[11] Cornish, K., Scerif, G., & Karmiloff-Smith, A. (2007). Tracing syndrome-specific trajectories of attention across the lifespan. Cortex: A Journal Devoted To The Study Of The Nervous System & Behavior, 43(6), 672-685.

[12] Gardner, H. (1998). A Multiplicity of Intelligences. Scientific American Presents, 18-23.

[13] Teulier, C., Lee, D., & Ulrich, B. (2015). Early Gait Development in Human Infants: Plasticity and Clinical Applications. Developmental Psychobiology, 57(4), 447-458.

[14] Bornstein, M. (1986). Frames of Mind: The Theory of Multiple Intelligences Howard Gardner. Journal Of Aesthetic Education, (2), 120. doi:10.2307/3332707

[15] Dugan, D. (Executive Producer), Rumley, L. (Producer), & Hickman, D. (Producer/Director). (2007). Race and intelligence: Science’s last taboo [Video]. Retrieved from part 7 http://www.dailymotion.com/video/xb9ing_race-and-intelligence-7-7_school

About mathias sager

Thinking and writing for happiness, painting colorfully, and enabling personal growth for all. Fostering co-operative and humanitarian principles, economic and social equality, as well as environmental sustainability. Using broad international experience and progressive, egalitarian and global outlook to promote care for the next generation.

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4 Responses to Nature v. Nurture in the Lifespan Development of People with Down Syndrome

  1. The last sentence, “It is important to remember (especially in developed western societies) that traditional IQ tests have little to do with achievement other than in the academic space. IQ and cognitive development is “a reflection of how we are brought up” is key. Great one Mathias. I worked with the mentally retarded for many years in my career. I walked away so blessed from the experience.

    • mathias sager says:

      I can imagine how precious your experience is. Thank you very much for sharing that. Thinking about mental retardation not as a difference, but primarily as a delay in development is helpful to appreciate these people as full human beings with specific strengths too (what sometimes seems to be a challenge in our conventional (language and math focused) performance society). The more I deal with the topic, the more compassion I develop.

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