6.4 Atypical Development and Disability Types

6.4 Atypical Development and Disability Types

Quick answer: PECT objective 0003.4 asks you to identify atypical progressions of cognitive, physical, social-emotional, behavioral, and linguistic development and to know characteristics, prevalence, etiologies, and educational implications of disabilities (the descriptor names developmental delays, learning disabilities, physical and other health-related disabilities). Use IDEA categories at a teacher-knowledge level. Distinguish delay vs. disability. Child Find is a duty. Do not invent Pennsylvania prevalence percentages. Do not treat second-language development as a learning disability.

Section 2.2 (0001.2) mapped typical sequences. This descriptor is the other side of the coin: when a pattern is not typical, what might it mean, and what is the teacher's job before Chapter 7's IEP and UDL details?

Atypical progressions: persistent, cross-setting, functional

'Atypical' is not 'different from the child next to them this morning.' Typical development is a range. Culture, opportunity, trauma, health, and English learning all shift timing. Atypical, for exam purposes, is a pattern that is:

• Far from the expected sequence given age and opportunity,
• Persistent across weeks and months, not a bad Tuesday,
• Visible in more than one setting (classroom, playground, home reports),
• Causing functional difficulty (learning, communicating, moving, relating, staying safe),
• Not better explained by lack of instruction, limited English, cultural communication style, or a temporary stressor alone.

One sample is not a category. Invented English spelling, a quiet month after immigration, or a PreK impulse at clean-up can be typical. L1-plus-English concern is different from English-only lag.

Delay versus disability

Developmental delay means a young child is substantially behind expected developmental rates in one or more areas (physical, cognitive, communication, social-emotional, adaptive). Federal IDEA allows states to use this category for children ages 3 through 9 (or a subset). Pennsylvania Chapter 14 defines developmental delay for a child who is at least 3 years of age and less than the age of beginners (kindergarten entry age in the district) and who meets measurement criteria: about 1.5 standard deviations below the mean on a standardized measure or a 25% delay in chronological age in one or more developmental areas (22 Pa. Code § 14.101). Teachers do not apply the formula; evaluators do. You need the idea: delay is an early-childhood eligibility path, not a forever medical brand.

Disability under IDEA Part B means the child meets criteria in a disability category and, by reason thereof, needs special education and related services. A medical diagnosis alone is not an IEP. A slow reader who is an English learner with little instruction is not automatically SLD.

Some children with delays catch up with early intervention. Some later meet an IDEA category. Some never need special education. Wait and see until Grade 4 is not Child Find. Panic-refer after one quiet week of English is not Child Find either.

Child Find

Child Find (IDEA 34 CFR § 300.111; Pennsylvania 22 Pa. Code § 14.121) is the LEA's affirmative duty to locate, identify, and evaluate children who may need special education, including preschoolers and children who are homeless, migratory, or attending private school. PreK–4 teachers are often the professionals who notice. Your job: document specific concerns, compare with typical progressions and with language/culture/opportunity factors, talk with families and specialists, and follow district referral procedures. You do not diagnose, promise an IEP, or skip parent rights. IEP-team roles sit in 0003.6; legal duties in 0003.8.

Screening is not a full evaluation. RTI/MTSS support does not legally delay a timely evaluation when a disability is suspected. For English learners, PDE is explicit: there is no waiting period before a disability determination may be considered, and a child must not be determined to have a disability if the determinant factor is lack of English proficiency. LIEP and special education are not mutually exclusive.

IDEA disability categories at teacher-knowledge level

IDEA lists 13 disability categories. Developmental delay is an additional age-limited option. You need characteristics and classroom implications, not a physician's lecture. Do not memorize fake Pennsylvania percentages; high- versus low-incidence is enough.

High-incidence (seen relatively often in inclusive rooms): specific learning disability (SLD), speech or language impairment, and often other health impairment (OHI) when ADHD or chronic health issues adversely affect educational performance. Some texts also place mild emotional disturbance and mild intellectual disability here.

Low-incidence (fewer students statewide, still entitled to FAPE in the least restrictive environment): deaf-blindness, deafness, hearing impairment, visual impairment including blindness, orthopedic impairment, traumatic brain injury, multiple disabilities. Autism was long grouped with low-incidence; identification has increased, so do not treat 'rare' as 'will never be in my PreK–4 room.'

Physical and other health-related disabilities in the Pearson example list map mainly to orthopedic impairment, OHI, TBI, and sensory categories. Learning disabilities map to SLD. Developmental delays map to the early-childhood path above.

Etiologies at teacher level: prenatal (genetics, prenatal exposures, infection), perinatal (prematurity, oxygen deprivation), postnatal (injury, illness, lead), and unknown. Unknown is common. Your job is educational impact, not assigning a cause in the hallway.

Prevalence: nationally, SLD is typically the largest school-age IEP category and speech/language is also high-incidence. Do not quote a made-up Pennsylvania percent on the exam. 'High-incidence' means you will teach these children in general education. 'Low-incidence' means fewer, not optional Child Find.

The favorite trap: L2 development as SLD

English learners may show:

• A silent period,
• BICS without CALP,
• L1 transfer errors,
• Slow English reading while L1 literacy or oral L1 is stronger,
• Code-switching.

None of those, by themselves, is SLD. SLD's federal definition excludes learning problems that are primarily the result of environmental, cultural, or economic disadvantage — and limited English is a determinant-factor bar. Compare L1 development, opportunity to learn, and response to language-supported instruction. If concerns remain in L1 and in English after appropriate ELD and content scaffolds, Child Find still applies. Dual identification is legal. English-only 'wait five years' is not PDE policy.

Scenario: Grade 2 referral urge

A child reads below grade level in English, mixes Spanish and English, and solves math with manipulatives and Spanish support. First stance: language history, L1 probe, ELPS-aligned scaffolds, and collaboration with the ESL teacher. Not an automatic SLD label. Not a ban on Spanish 'to prove' disability.

Scenario: PreK motor and language

A four-year-old with ample opportunity still has no two-word combinations in the home language, little pretend play, and motor skills far below the typical range. That multi-domain, L1-involved pattern is Child Find — possibly developmental delay evaluation — not 'wait until English appears.'

Exam traps for 0003.4

• Treating typical L2 (silent period, BICS/CALP gap, transfer) as SLD.
• Inventing Pennsylvania prevalence percents.
• Equating delay with a school-age disability label, or refusing to refer because 'it's just a delay.'
• Thinking high-incidence means separate-school placement, or low-incidence means you will never see the child.
• Diagnosing etiology yourself, or waiting for a doctor's letter before any Child Find step.
• Confusing this descriptor with UDL/IEP implementation (0003.5–0003.8).

If the stem is an English learner whose only 'deficit' is English, choose language support and caution. If the stem is multi-domain, persistent, and present in L1, choose Child Find.