Developmental Differences: Lecture Notes PDF

Developmental Differences Dr. Shue Ling Chong PSGY1013 - Developmental Psychology Overview What are developmental differences? Prevalence and causes. Examples of developmental differences. Profiles of difference / difficulty. Medical and Social models of disability. Neurodiversity....

Developmental Differences Dr. Shue Ling Chong PSGY1013 - Developmental Psychology Overview What are developmental differences? Prevalence and causes. Examples of developmental differences. Profiles of difference / difficulty. Medical and Social models of disability. Neurodiversity. 2 Learning objectives By the end of the lecture you should be able to: Explain the different ways a developmental difference may be caused. Describe the profile of some developmental differences. Understand the medical and social models of disability. 3  Divergence from typical What are development, identified in childhood. developmental Often lifelong, although some differences? remit in adulthood. Can include atypical cognitive, social, behavioural, language, or motor development. As many as 1:10 children may have a developmental difference (Boyle et al., 2011). 4 What causes developmental differences? Some developmental differences have a known genetic basis. Can be inherited or due to a random mutation. These include: Down’s Syndrome Fragile X Rett’s Syndrome Turner Syndrome Williams Syndrome 5 What Causes developmental differences? (2) Other differences have a putative genetic basis. Researchers assume there is a genetic basis because of circumstantial evidence. These include: Autism Spectrum Disorder. Attention Deficit Hyperactivity Disorder. Language Disorders 6 What Causes developmental differences? (3) Some differences have an environmental cause, and others can be influenced by environmental factors. Access to therapy. Features of the home environment. Nutrition. Cerebral Palsy has a purely environmental cause. 7 Diagnosis Usually parents take their child to GP when they have concerns. The GP refers the child to specialist assessment services. Assessments completed by pediatricians and clinical psychologists: History of difficulty. Standardized assessments. Observations. Questionnaires completed by parents and teachers. 8 Profiles of Developmental differences Autism ADHD Dyslexia 9 Autism First described in the mid 20th Century. By Leo Kanner (1943) and Hans Asperger (1944). Marked by differences in: Social interaction. Communication. Restricted Interests and Repetitive Behaviours. Lifelong differences that are maintained into adulthood. 10 Characteristics of autism 1 in 44 children in the US have autism (CDC, 2018) Heterogeneous presentation: Can be present in people with high IQ as well as in people with low IQ. Historically more common in boys than girls. Approximately 40% autistic people are nonverbal. Putative genetic cause - not caused by vaccines or bad parenting. 11 Theories of AUTISM 1 Theory of mind hypothesis (Baron-Cohen et al, 1985) Children completed an unexpected transfer test. Autistic children performed worse than verbal- and nonverbal-ability matched groups. Could this account for a broad range of social difficulties? 12  Theories of autism 2 Theory of Weak ‘Central Coherence’ (Frith, 1989) limited understanding of big- picture, overly focused on details Proposed to account for non-social differences and perceptual strengths seen in autism. Autistic individuals were faster and more accurate on the embedded figures task and the block design task. 13 Attention Deficit Hyperactivity Disorder (ADHD) ADHD was first recognised in the early 1900s as “Hyperkinetic disorder”. It was renamed ADHD in 1987. Marked by differences in: Attention – unresponsive yet distractible. Hyperactivity – seem to have an internal dynamo, fidgeting, impossible to sit still. Impulsivity – unwilling to queue, unable to await turn in games. 14 Characteristics of ADHD Occurs in 8 in100 people (Faraone et al, 2003). More common in boys than girls. Some children remit, whereas others maintain diagnoses into adulthood. High heritability estimates – 75% (Saviouk et al, 2011). But affected by environmental factors such as diet (McCann et al, 2007). 15 Theories of ADHD Barkley (1997) Sonuga-Barke (2005) Primary differences in Primary differences with executive functioning. reward and motivation. Difficulty with delayed gratification. 16 Language disorders Prevalence about 7:100. More common in boys than girls. Language areas of the brain implicated in some of these disorders: Broca’s area Wernicke’s area 17 Developmental dyslexia Marked by difficulty in reading and spelling that is not explained by generally poor ability. Struggle to identify how many syllables a word has. Struggle to identify rhyming words. Difficulty discriminating between sounds of different letters. Although it has a genetic basis, it is also affected by environmental factors, notably whether or not the language is ‘transparent’. Developmental dyslexia is much more common in non- transparent languages like English than in transparent languages like Italian and Japanese. 18 MEDICAL vs Social MODELS OF DISABILITY 19 Medical model of disability Under the medical model, these impairments or differences should be ‘fixed’ or changed by medical and other treatments, even when the impairment or difference does not cause pain or illness. 20 Social model of disability The social model of disability says that disability is caused by the way society is organised, rather than by a person’s impairment or difference. It looks at ways of removing barriers that restrict life choices for disabled people. 21 Medical and Social Models of disability 22 Neurodiversity Difference not Disability. Neurological differences are respected as any other human variation. This view celebrates different forms of communication and self-expression. Not searching for a cure. 23 Activity: Writing about developmental differences The following paragraph is a medical description of autism. Can you rephrase the text below to reflect a social model of disability? "Autism is a spectrum of neuropsychiatric disorders characterized by deficits in social interaction and communication, and unusual and repetitive behaviour. The degree of autism varies from mild to severe in different children. Severely afflicted patients are non-verbal. The cause (or causes) of autism are not yet fully understood. However, it is believed that at least some cases involve an inherited or acquired genetic defect. Researchers have proposed that the immune-system, metabolic, and environmental factors may play an important part as well. The optimal treatment of autism involves an educational program that is suited to the child's developmental level." 24 Activity: Writing about developmental differences (2) "Autism is a spectrum of neuropsychiatric disorders characterized by deficits in social interaction and communication, and unusual repetitive behavior. The degree of autism varies from mild to severe in different children. Severely afflicted patients are non- verbal. The cause (or causes) of autism are not yet fully understood. However, it is believed that at least some cases involve an inherited or acquired genetic defect. Researchers have proposed that the immune-system, metabolic, and environmental factors may play an important part as well. The optimal treatment of autism involves an educational program that is suited to the child's developmental level." 25  Activity: Writing about developmental differences (3) "Autism is a spectrum of "Autism is a spectrum of neuropsychiatric neuropsychiatric disorders characterized differences characterized by differences in by deficits in social interaction and social interaction and communication, and communication, and unusual repetitive repetitive behavior. The presentation of behavior. The degree of autism varies autism varies in different children. Some from mild to severe in different children. autistic individuals are non-verbal. The Severely afflicted patients are non- cause (or causes) of autism are not yet verbal. The cause (or causes) of autism fully understood. However, it is believed are not yet fully understood. However, it that at least some cases involve is believed that at least some cases an inherited or acquired genetic involve an inherited or acquired genetic differences. Researchers have proposed defect. Researchers have proposed that that the immune-system, metabolic, and the immune-system, metabolic, and environmental factors may play an environmental factors may play an important part as well. Autistic people can important part as well. The optimal be supported by making appropriate treatment of autism involves an adjustments to their environments." educational program that is suited to the child's developmental level." 26 Summary Many developmental differences have either a putative or a definite genetic basis. We reviewed: Autism ADHD Dyslexia (but there are many more – see the textbook for descriptions). The Neurodiversity Movement is currently changing the way we conceive of developmental differences. 27 Further work Reading: Mitchell & Zeigler – Chapter 6 – Developmental Disorders. Optional: Mitchell & Zeigler – Chapter 7 – Autism. 28