Developmental Challenges for Individuals with Intellectual Disability

by Barbara Tylenda, PhD, Rowland Barrett, PhD, and Henry Sachs III, MD

Development is a complex process of growth and change through which children acquire a variety of skills and abilities that allow them to understand and function in their world. The normal trajectory of development enables a child to progress from complete dependency on others to near- or complete independency of his/her needs and well-being.

July 2014 Vol. 30, No. 7CABL logoThis article was published in the Brown University Child and Adolescent Behavior Letter in cooperation with Bradley Hospital.

Although there is great variability in development, there are earlier and later limits to what is considered “normal/ typical” development. Statistically, children with intellectual disability (ID) are those who develop at a rate significantly below average — the lowest 3% on the normal, bell-shaped curve distribution — indicating why ID is called a “developmental disability.”

These children make progress at a rate that is significantly slower than is expected of children their age. However, just as the development of children who do not have ID varies, so does the development of children with ID. Further, for any child with ID, the development of different areas (e.g., cognitive abilities, language and speech skills, gross motor skills, fine motor skills, social-emotional skills, and play skills) may proceed at different rates, on different timelines, and in different orders. As a result, the timetable for achievement of developmental milestones for a child with ID can be difficult to predict as well as eventual developmental outcomes. However, over time, such trajectories become more predictable based on the child’s prior rates and breadth of performance. child playing

Variables key to the eventual developmental progression for any child with ID will include the following:

  • The child’s inborn biological and neurological capacity (which set the general limits for the rate and eventual endpoints of development)
  • The ongoing environmental factors to which the child is exposed (e.g., type and amount of stimulation)
  • Any associated disabilities or medical problems of the child
  • The child’s support network’s ability to assist him/her in addressing these challenges.

Disruption of Mastery of Developmental Skills Specific to Developmental Periods

The mastery of developmental “skills” specifically associated with each developmental period can present unique challenges for a child or adolescent with ID. A disruption in the mastery of specific developmental skills also can present unique challenges for the child or adolescent’s caregivers and family, in how they initiate as well as respond to the child.


Infancy is characterized by the development of attachment, self-regulation, and environmental awareness and exploration. ID and associated disorders may disrupt mastery in each of these areas. Many developmental processes in infancy focus on strengthening attachment. Eye contact, a social smile, and cooing and other vocalizations often are delayed or nonexistent in children with ID. For infants with significant neurological or physical disabilities, uncertainty about their survival or prognosis, long-term postnatal hospitalizations, or prolonged intrusive medical interventions also inhibit normal attachment.

Families often experience anger, denial, sorrow, and a prolonged grieving process in response to having a child with ID. This also may interfere with the attachment process. In children with more subtle delays, the inability to achieve milestones at expected intervals may lead to misgivings about parental skills and increasing frustration. Autism spectrum disorders, often associated with ID, create further obstacles to attachment.

Delays in motor coordination and exploration of the environment often create a greater dependence on caregivers that is a harbinger of future interactive patterns. This may be enhanced by comorbid medical disorders, such as seizures, that enhance parental vigilance. Conversely, social withdrawal and isolation are frequent presentations.

Early Childhood

Many children’s ID and associated delays are identified during this period. Parental response, both emotionally and in terms of expectations, impacts on this period of personal mastery. Maintaining unrealistic expectations of trying to “prove the experts wrong” leads to increasing frustration and tension in the parent-child relationship. Conversely, removing or minimizing expectations may inhibit the development of many key skills. This may create an environment of overprotection or chronic parental apathy that squelches individual initiative.

Language development is usually delayed in persons with ID. Mild delays are often overlooked or misinterpreted. Early intervention, which can be very helpful, is often unintentionally delayed. Deficits in language and communication development are some of the best predictors of behavioral difficulties in children with developmental disabilities. Frustration at not being able to communicate needs or desires may lead to disruptive, aggressive, or self-injurious behavior. Social failures are often the result of an inability to follow the flow of communication and basic interpersonal cues. Isolation or increased reliance on selected caregivers may be inadvertently reinforced. In this regard, it is important to recognize that children with specific language disorders may develop effective alternative communication systems to express their needs.

Self-care skills are frequently delayed. Associated fine and gross motor delays may prevent children from successfully dressing, going to the toilet, or feeding themselves. Children with less severe delays may express the desire to perform these tasks without the requisite skills. This may lead to increasing conflict with caregivers. For those with a more severe form of ID, there is often the lifelong inability to contribute effectively to activities of daily living. Opportunities for child care may be greatly reduced by the child’s lack of self-care skills. Unfortunately, it is just those parents who must continue providing their children with intensive assistance who would benefit most from more readily available child care.

Spontaneous, meaningful play may be delayed or missing. Children with a more severe form of ID may engage in seemingly undirected or self-stimulatory behavior instead of appropriate play. Children with lesser delays may only develop some symbolic play as they are about to enter school. Isolated or parallel play may predominate, especially when communication skills are significantly impaired.

As with all children, many factors during this formative period contribute to personality development. The challenges of skill mastery, communication, emotional and physiological self-regulation, and how caregivers address these issues have significant implications. For children with milder-severity ID, self-esteem, trust, and perceived competence form the basis of interpersonal relationships and a sense of self in the world. For those with more severe delays, the caregiver’s ability to assist the child effectively in regulating responses to internal and environmental stimuli helps create a lifelong style of behavior.


For many children with ID, beginning school is the first exposure to a large number of children without disabilities. It may be the first time descriptors such as “intellectually disabled,” “slow learner,” or other pejorative terms are encountered. This may be particularly challenging to children with mild ID. While increased academic mainstreaming has elevated the awareness of many typical children regarding disabilities, children with ID are often still perceived as different and the target of peer taunting and rejection. As important, they perceive themselves as different. This becomes particularly challenging in the later elementary grades as peers become less tolerant of anyone seen as different. It is also a time when children with mild- to moderate-severity ID become increasingly aware of their limitations. Social withdrawal, isolation, and depression often manifest during this period. Some children display externalizing or acting-out behavior as an increasing desperation to be socially accepted coincides with peers’ increased willingness to use them as foils.

Participation in extracurricular and community activities is a hallmark of this age. Athletics may be inaccessible for some with significant associated physical handicaps. The nationwide Special Olympics initiative and greater understanding and support from many school districts have increased the participation rate of children with ID and other developmental delays in athletics. Group activities such as scouting have created subgroups that are more geared toward children with special needs but may isolate them from the mainstream, increasing their awareness of perceived differences. Dance and martial arts classes are often very well received by parents and children alike.

Most children with ID need support in the classroom in terms of either special resource support or placement in a self-contained special education classroom. As peers tackle more demanding language and abstract concepts, children with mild ID increasingly struggle to keep up. Academic failures are common. For children with more severe delays, the goals of education often change from preparation for higher education to life skills and vocational activities, further differentiating them from peers. The rigid demands of an academic schedule may be very different from the previous flexibility of home. Children with ID will have greater difficulty adapting to this change. This difficulty often will be expressed behaviorally, as they are unable to convey via communicative skills the ensuing frustration and confusion. The subtleties of communication and behavioral routines, well learned by families, may be lost on teachers caring for numerous children with varying special needs.

Barbara Tylenda, PhD, ABPP, is chief psychologist at the Center for Autism and Developmental Disabilities (CADD) at Bradley Hospital; a clinical associate professor in the department of psychiatry and human behavior (DPHB) at Alpert Medical School of Brown University, and associate director of the Brown University Clinical Psychology Training Consortium.

Rowland Barrett, PhD, is an associate professor in the DPHB at The Warren Alpert Medical School of Brown University.

Henry Sachs III, MD, is the medical director of Lifespan pediatric behavioral health services; chief medical officer at Bradley Hospital, and clinical assistant professor in the DPHB at Alpert Medical School of Brown University; .