Intelligence Development in Children

3.1 Intelligence

The epigenetic perspective, which considers the capacity of genetics and environment to influence each other in the acquisition of intelligence, personality, and other psychological traits, has come to the fore. While Terman focused on the abstract thinking dimension of intelligence, Thorndike emphasized the ability to learn. Today, intelligence is defined more as the ability to adapt to the environment.

3.1.1 Psychometric Theories

Psychometric theories evaluate intelligence as a mixture of measurable mental abilities. Psychometric intelligence is influenced by biological origins as well as education, socioeconomic status, family environment, and cultural factors. Intelligence shows a settling-in characteristic around the age of six and has a moderate effect on academic achievement.

3.1.2 Cognitive Development Theories

Alongside the psychometric perspective, which defines intelligence as an ability, cognitive development theories fundamentally evaluate intelligence as a process of adaptation to the environment. Swiss psychologist Piaget believed that infants and children have a different cognitive capacity than adults and must pass through four cognitive stages before reaching adult cognitive capacity.

Sensory-motor stage (0-2 years) Infants discover the relationship between their senses and motor behavior. Object permanence is acquired.

Preoperational stage (2-7 years) Children develop the capacity to use symbols such as language. Pretend play is common. Egocentric thinking is common.

Concrete operational stage (7-11 years) Logical thinking develops. Conservation of concepts such as mass, weight, number, length, area, and volume, and classification skills are acquired.

Formal operational stage (11 years and older) Abstract thinking skills develop. Scientific thinking, probabilistic thinking, and hypothesis development skills are acquired.

Another representative of cognitive development theories, Vygotsky, argues that superior cognitive functions unique to humans develop on the basis of social interaction. Another theory that emerged to explain mental development is the information processing theory. This theory likens the functioning of the human mind to a computer model, evaluating all stimuli received from the environment as input and the responses resulting from the processing of this input as output.

3.1.3 Current Theories

The broad scope of intelligence has led to the development of new theories in recent times. According to Sternberg's triarchic theory of intelligence, intelligence requires the balanced functioning of three domains. These three domains are intelligence, creative intelligence, and practical intelligence.

Gardner's theory of multiple intelligences posits that intelligence is not a single structure but a multiple structure. According to the theory of multiple intelligences, nine structures have been defined. These intelligence structures are, in order, verbal, logical-mathematical intelligence, visual-spatial intelligence, musical intelligence, bodily-kinesthetic intelligence, interpersonal intelligence, intrapersonal intelligence, naturalistic intelligence, and existential intelligence. Children diagnosed with mental disability, who have low IQ scores overall, may also be better than others in certain specific areas. Therefore, instead of specifying a single intelligence score, an assessment based on multiple intelligence structures should be created.

3.2 Intellectual Disability

3.2.1 Definition

It causes impairment in primary adaptive functions such as communication, self-care, and social skills. These children experience delays in areas such as speech, cognitive abilities, and motor development compared to their peers, and they begin to be distinguished when they start preschool education.

3.2.2 Causes of the Disease

Down syndrome, fragile X syndrome, and fetal alcohol syndrome account for up to 30% of cases diagnosed with mental disability. Autosomal recessive genetic disorders such as Tay-Sachs disease and phenylketonuria cause mental disability. During meiosis, breaks or division errors may occur in the chromosomes of egg and sperm cells. This leads to chromosomal abnormalities. The most common of these is Down syndrome. Prader-Willi syndrome, Angelman syndrome, and Williams syndrome are other types. Disorders causing mental retardation based on sex chromosome abnormalities are Klinefelter syndrome (XXY) and Turner syndrome (X0). Deficiencies during pregnancy and early years, malnutrition, and viral and bacterial infections are triggers. Inappropriate medication use during pregnancy and exposure to lead or other heavy metals are other triggering factors.

3.2.3 Diagnosis

The DSM-4 system determines the severity of mental disability based on cut-off points from standardized intelligence tests such as the Wechsler and Stanford-Binet. IQ scores between 50-55 and 70 are classified as mild, between 35-40 and 50-55 as moderate, between 20-25 and 35-40 as severe, and 20-25 as profound.

3.2.4 Epidemiology

The prevalence of intellectual disability in society is 1%. Severe disability occurs at a rate of 6 per thousand. Boys are diagnosed with mild and severe intellectual disability more often than girls.

3.2.5 Prognosis

85% of individuals with the disorder have mild intellectual disability and fall into the educable category. The rate of individuals with moderate mental disability is 10%. The most severe type occurs at a rate of 1-2%.

3.2.6 Associated Disorders

Attention deficit, hyperactivity disorder, mood disorders, and autism spectrum disorders may accompany mental disability. Aggression and destructive behaviors may be observed in severe cases.

3.2.7 Treatment

There is no common therapy or medication treatment process for intellectual disability. Instead, symptomatic treatment of the disorder and behavioral therapies are recommended. Although there is no medication specifically for treating intellectual disability, medication may be used to suppress aggression, restlessness, and self-injurious behaviors. It should be planned on an individual basis. Creating a family-centered intervention plan, ensuring professionals work in a planned manner, highlighting strengths, enhancing self-efficacy, considering interpersonal differences, and peer support are important in treatment.