Introduction
This lesson addresses the characteristics of students with disabilities, a core knowledge area assessed on the teacher certification exam. The content covers typical and atypical human growth and development across cognitive, speech/language, social/emotional, and physical domains. It also covers the types and characteristics of disabilities recognized under federal special education law and the similarities and differences among students with and without disabilities.
This study guide covers three major areas: (1) typical developmental milestones across all domains, (2) the 13 IDEA disability categories and their defining characteristics, and (3) how students with disabilities compare to their typically developing peers.
(1) Typical Human Growth and Development
Understanding typical development is the foundation for recognizing atypical patterns. Special education teachers use knowledge of expected developmental milestones to identify when a child is falling behind or developing differently.
Cognitive Development
Cognitive development refers to how children acquire the ability to think, reason, solve problems, and understand the world around them. Key theories and milestones include:
- Piaget's stages:
- Sensorimotor (birth to 2 years): Learning through senses and motor actions; development of object permanence
- Preoperational (2 to 7 years): Symbolic thinking emerges; egocentric perspective; language development accelerates
- Concrete operational (7 to 11 years): Logical thinking about concrete events; understanding of conservation, classification, and seriation
- Formal operational (11+ years): Abstract and hypothetical thinking; deductive reasoning; metacognition
- Vygotsky's zone of proximal development (ZPD): The range between what a child can do independently and what they can do with adult guidance or peer collaboration. Effective instruction targets the ZPD through scaffolding.
- Information processing: How children take in, store, and retrieve information. Key components include attention, working memory, long-term memory, and executive functions (planning, organizing, self-monitoring).
- Atypical patterns: Children with intellectual disabilities, specific learning disabilities, or traumatic brain injuries may show delayed or uneven cognitive development. Processing speed, working memory, and executive functioning are commonly affected areas.
TEST READY TIP
Questions about cognitive development on the teacher certification exam frequently ask you to match a classroom behavior to the correct Piagetian stage. A kindergartner who insists that a taller glass holds more liquid than a shorter, wider glass is demonstrating preoperational thinking, while a fifth grader who can explain why the amounts are equal has reached concrete operational understanding of conservation.
Speech and Language Development
Speech refers to the physical production of sounds, while language refers to the system of symbols and rules used to communicate meaning. Both develop in predictable sequences:
| Age | Speech Milestones | Language Milestones |
|---|---|---|
| 0 to 6 months | Cooing, babbling, vocal play | Responds to voices; recognizes name |
| 6 to 12 months | Canonical babbling (ba-ba, da-da) | Understands simple words; first words emerge |
| 12 to 24 months | Approximations of adult words; 50+ words by 24 months | Two-word combinations; vocabulary expansion |
| 2 years | Speech about 50% intelligible to strangers | Two- to three-word sentences; asks simple questions |
| 3 years | Speech about 75% intelligible to strangers | Three- to four-word sentences; asks questions; tells simple stories |
| 4 to 5 years | Speech about 90 to 100% intelligible; most sounds mastered by age 5 to 6 | Complex sentences; tells stories; uses grammar rules |
| 6 to 8 years | Later-developing sounds (for example, /r/, /s/, /th/) mastered by age 7 to 8 | Understands figurative language; reading begins |
- Receptive language (understanding) typically develops before expressive language (production)
- Pragmatic language (social use of language) includes turn-taking, topic maintenance, and understanding nonverbal cues
- Atypical patterns: Late onset of babbling, limited vocabulary at 18 to 24 months, difficulty with pragmatics, or persistent articulation errors beyond expected ages may signal a speech or language impairment
COMMON TRAP
A common error is to treat articulation problems as the only form of speech or language impairment. The category also includes receptive language disorders, expressive language disorders, fluency disorders such as stuttering, and voice disorders. A student who speaks clearly but cannot follow multi-step directions or maintain a conversation may still qualify under Speech or Language Impairment.
Social/Emotional Development
Social and emotional development encompasses how children form relationships, regulate emotions, and develop a sense of self.
- Attachment theory (Bowlby): Secure attachment in infancy forms the foundation for healthy social and emotional development. Insecure attachment patterns (avoidant, ambivalent, disorganized) may affect a child's ability to form relationships and regulate emotions throughout life.
- Erikson's psychosocial stages (most relevant to school-age):
- Trust vs. Mistrust (0 to 1 year): Consistent caregiving builds trust
- Autonomy vs. Shame and Doubt (1 to 3 years): Developing independence
- Initiative vs. Guilt (3 to 6 years): Planning and taking on new challenges
- Industry vs. Inferiority (6 to 12 years): Mastery of academic and social skills
- Identity vs. Role Confusion (12 to 18 years): Forming personal identity
- Self-regulation: The ability to manage emotions, attention, and behavior develops gradually throughout childhood. Children with emotional disturbance, ADHD, or autism spectrum disorder may have significant challenges with self-regulation.
- Social skills progression: Parallel play (toddlers) to cooperative play (preschool) to organized games with rules (school-age) to complex peer relationships and perspective-taking (adolescence)
Physical and Motor Development
Physical development includes both gross motor skills (large movements) and fine motor skills (small, precise movements).
| Age | Gross Motor | Fine Motor |
|---|---|---|
| 0 to 6 months | Head control, rolling over | Grasping reflexes, reaching |
| 6 to 12 months | Sitting, crawling, pulling to stand | Pincer grasp, transferring objects |
| 1 to 2 years | Walking, climbing stairs | Stacking blocks, scribbling |
| 3 to 5 years | Running, jumping, hopping, throwing | Drawing shapes, using scissors, writing letters |
| 6+ years | Complex coordination, sports skills | Handwriting fluency, detailed drawing |
Development follows two key patterns: cephalocaudal (head to toe, meaning head control before walking) and proximodistal (center to extremities, meaning trunk control before finger control).
(2) The 13 IDEA Disability Categories
Under the Individuals with Disabilities Education Act (IDEA), students must be identified with one of 13 disability categories AND the disability must adversely affect educational performance to be eligible for special education services.
High-Incidence Disabilities
These categories make up the majority of students receiving special education services:
| Category | Key Characteristics |
|---|---|
| Specific Learning Disability (SLD) | Disorder in one or more basic psychological processes involved in understanding or using language. Manifests as difficulties in listening, thinking, speaking, reading (dyslexia), writing (dysgraphia), or mathematics (dyscalculia). Most common category, approximately 32 to 33% of all students with IEPs. |
| Speech or Language Impairment (SLI) | Communication disorder that adversely affects educational performance. Includes articulation disorders, fluency disorders (stuttering), voice disorders, and language disorders (expressive, receptive, or mixed). Second most common category. |
| Other Health Impairment (OHI) | Limited strength, vitality, or alertness due to chronic or acute health problems that adversely affect educational performance. Includes ADHD, epilepsy, sickle cell anemia, diabetes, heart conditions, and lead poisoning. ADHD is commonly cited as the most frequent condition served under OHI. |
| Autism Spectrum Disorder (ASD) | Developmental disability significantly affecting verbal and nonverbal communication and social interaction. Characteristics include restricted interests, repetitive behaviors, sensory sensitivities, and difficulty with social reciprocity and perspective-taking. Fastest-growing category. |
| Emotional Disturbance (ED) | Condition exhibiting one or more characteristics over a long period and to a marked degree: inability to learn not explained by other factors; inability to build or maintain relationships; inappropriate behaviors or feelings; pervasive unhappiness or depression; physical symptoms or fears associated with school problems. |
TEST READY TIP
The teacher certification exam is likely to present a scenario describing a student's behavior and ask you to identify the most appropriate disability category. A third grader who reads accurately but cannot recall what was read, reverses letters when writing, and struggles to memorize math facts is showing a pattern consistent with Specific Learning Disability, not Intellectual Disability, because the difficulties are specific to academic skill areas rather than global.
Low-Incidence Disabilities
These categories are less common but require specialized knowledge:
| Category | Key Characteristics |
|---|---|
| Intellectual Disability (ID) | Significantly subaverage general intellectual functioning (IQ typically below 70) AND concurrent deficits in adaptive behavior (conceptual, social, practical skills). Classified as mild, moderate, severe, or profound. Manifests during the developmental period. |
| Multiple Disabilities | Combination of two or more disabilities (for example, intellectual disability and blindness) that creates educational needs that cannot be addressed in a program designed for a single disability. Does NOT include deaf-blindness. |
| Orthopedic Impairment | Severe physical impairment that adversely affects educational performance. Includes congenital anomalies (for example, clubfoot, spina bifida), conditions from disease (for example, poliomyelitis, bone tuberculosis), and conditions from other causes (for example, cerebral palsy, amputations, fractures). |
| Hearing Impairment / Deafness | Hearing impairment: Permanent or fluctuating hearing loss that adversely affects educational performance but is not included under deafness. Deafness: Hearing loss so severe that the student cannot process linguistic information through hearing, with or without amplification. |
| Visual Impairment (Including Blindness) | Impairment in vision that, even with correction, adversely affects educational performance. Includes both partial sight and blindness. Students may use Braille, large print, assistive technology, or orientation and mobility services. |
| Deaf-Blindness | Concomitant hearing and visual impairments causing severe communication, developmental, and educational needs that cannot be accommodated in programs solely for deaf or blind students. |
| Traumatic Brain Injury (TBI) | Acquired injury to the brain caused by an external physical force. May result in total or partial functional disability or psychosocial impairment affecting cognition, language, memory, attention, reasoning, abstract thinking, judgment, behavior, or physical functions. |
| Developmental Delay | For children ages 3 to 9 (or a subset, as determined by the state): delay in one or more areas, including physical, cognitive, communication, social/emotional, or adaptive development. Allows early identification without requiring a specific disability label. |
COMMON TRAP
A frequent error is to classify a student with ADHD under Emotional Disturbance or Specific Learning Disability. Under IDEA, ADHD is not a standalone category. It is most commonly served under Other Health Impairment because it involves limited alertness and executive functioning due to a chronic health condition. A student with ADHD may also qualify under ED or SLD if the criteria for those categories are independently met, but ADHD alone falls under OHI.
(3) Similarities and Differences: Students With and Without Disabilities
A core principle of special education is that students with disabilities are more like their non-disabled peers than they are different. Understanding both the commonalities and the unique characteristics is essential for effective instruction.
What Students Share
- Same basic needs: All students need belonging, safety, positive relationships, meaningful engagement, and opportunities for success
- Same developmental trajectory: Students with disabilities typically follow the same sequence of development as their peers. They may progress at a different rate or plateau at a different level, but the sequence is generally preserved
- Same curricular standards: Under IDEA, students with disabilities have the right to access the general education curriculum. The expectation is participation in grade-level standards with appropriate supports
- Motivation and self-concept: All students are motivated by success, recognition, and a sense of competence. Repeated failure can damage self-esteem and motivation in any student
Key Differences to Understand
- Rate of learning: Students with disabilities may require more time, more repetitions, and more explicit instruction to master the same content
- Generalization: Students with disabilities often struggle to transfer skills learned in one context to new situations. Direct instruction in generalization is frequently needed
- Executive functioning: Difficulties with planning, organizing, initiating tasks, self-monitoring, and flexible thinking are common across many disability categories
- Social processing: Students with ASD, ED, or intellectual disabilities may have difficulty reading social cues, understanding unspoken rules, or engaging in age-appropriate social interactions
- Sensory processing: Some students, particularly those with ASD or sensory processing differences, may be over- or under-responsive to sensory input such as sound, light, touch, or movement
- Communication: Students may have delays or differences in how they express themselves, understand language, or use language socially
Person-First vs. Identity-First Language
Special educators should be aware of preferred language conventions:
- Person-first language puts the person before the disability: "a student with autism," "a child with a learning disability." This is the standard in professional and legal contexts.
- Identity-first language is preferred by some communities, particularly in the Deaf community ("Deaf person") and some autistic self-advocates ("autistic person").
- Best practice: Follow the preference of the individual or community when known. In professional writing and on the teacher certification exam, person-first language is the expected convention.
TEST READY TIP
Exam questions about similarities and differences often ask you to select the statement that best reflects how a student with a disability compares to typically developing peers. The correct answer typically emphasizes that the student follows the same developmental sequence but at a different rate, rather than suggesting a completely different developmental path or the absence of shared needs.
(4) Key Takeaways
- Typical developmental milestones across all four domains (cognitive, speech/language, social/emotional, physical) provide the baseline for identifying atypical development
- The 13 IDEA disability categories each have distinguishing characteristics, with the high-incidence categories (SLD, SLI, OHI, ASD, ED) appearing most frequently on the exam
- SLD is the most common category (about one-third of all students with IEPs), and ADHD falls under Other Health Impairment
- Eligibility requires two prongs: the student must have one of the 13 disabilities AND the disability must adversely affect educational performance
- Students with disabilities follow the same developmental sequence as their peers. They may differ in rate, but the trajectory is the same
- Generalization is a common challenge: Students with disabilities often need explicit instruction to transfer skills across settings and contexts
- Development is interconnected: Delays in one domain, such as language, frequently affect other domains, such as social skills and academic achievement
- Person-first language is the expected convention in professional contexts unless the individual or community prefers identity-first language