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Disability Wiki

Intellectual & Developmental Disabilities

All people have the right to make decisions about their own lives, to be included in community, and to receive support that respects their autonomy and dignity. This page centers the expertise of self-advocates with intellectual and developmental disabilities.

Intellectual and developmental disabilities (IDD) include conditions present from birth or early childhood that affect cognitive development, adaptive skills, or both. People with IDD have fought for decades for the right to live, work, learn, and make choices in their communities — not in institutions or segregated settings.

Understanding Intellectual and Developmental Disabilities

Section titled “Understanding Intellectual and Developmental Disabilities”

What Are Intellectual and Developmental Disabilities?

Section titled “What Are Intellectual and Developmental Disabilities?”

Developmental disability is a broad category of conditions that:

  • Begin before age 22
  • Are likely to continue throughout life
  • Result in substantial limitations in major life activities

Intellectual disability specifically involves:

  • Significant limitations in intellectual functioning (reasoning, learning, problem-solving)
  • Limitations in adaptive behavior (everyday social and practical skills)
  • Onset during developmental period

Not all developmental disabilities involve intellectual disability. For example, autism is a developmental disability, but many autistic people do not have intellectual disability.

Self-Advocates Lead the Way

Section titled “Self-Advocates Lead the Way”

People with intellectual and developmental disabilities have been at the forefront of fighting for their rights. Key principles from the self-advocacy movement:

“Nothing About Us Without Us”: People with IDD must be involved in decisions affecting their lives.

“Label Jars, Not People”: People are more than diagnoses.

Presuming competence: Assume people understand and can participate, then provide supports — rather than assuming incompetence.

Person-first vs. identity-first: Many people with IDD prefer person-first language (“person with a disability”), while some prefer identity-first (“disabled person”). Ask individuals their preference.

Conditions and Experiences

Section titled “Conditions and Experiences”

Intellectual Disability

Section titled “Intellectual Disability”

Intellectual disability (formerly called “mental retardation,” a term now considered offensive) affects how quickly and easily someone learns and applies new information.

Understanding intellectual disability:

  • IQ tests measure only certain kinds of intelligence
  • Adaptive functioning (daily living skills) matters as much as IQ
  • Support needs vary enormously person to person
  • People with intellectual disability can learn, grow, and contribute throughout life

Support levels: Formerly described as “mild, moderate, severe, profound” — now often described by support needs (intermittent, limited, extensive, pervasive).

Important: Intellectual disability means learning differently and potentially needing support — not inability to learn, have meaningful lives, or make choices.

Down Syndrome

Section titled “Down Syndrome”

Genetic condition caused by an extra chromosome 21 (trisomy 21). Most common chromosomal cause of intellectual disability.

Understanding Down syndrome:

  • Wide range of abilities and support needs
  • Many people with Down syndrome live independently, work, and have relationships
  • May have associated health conditions (heart conditions, thyroid issues, hearing/vision)
  • Life expectancy has increased dramatically with medical advances

Self-advocates: People with Down syndrome are increasingly visible advocates, business owners, actors, and more.

Typical healthcare: Pediatric and adult specialists following Down syndrome health guidelines, regular screenings for associated conditions.

Organizations:

  • Self Advocates Becoming Empowered (SABE) — led by people with developmental disabilities
  • National Down Syndrome Society (NDSS)
  • Down Syndrome Association (UK)
  • Global Down Syndrome Foundation

Cerebral Palsy

Section titled “Cerebral Palsy”

Cerebral palsy (CP) is a group of disorders affecting movement, muscle tone, and posture caused by damage to the developing brain. CP is a developmental disability, though most people with CP do not have intellectual disability.

Understanding CP:

  • Highly variable — some people have mild symptoms, others significant
  • Motor function is affected; cognition may or may not be
  • Not progressive but effects may change over time
  • Some people use AAC (augmentative and alternative communication)

See also: Physical Disabilities for more on CP.

Fragile X Syndrome

Section titled “Fragile X Syndrome”

Genetic condition causing intellectual disability and often autism. Most common inherited cause of intellectual disability.

Understanding Fragile X:

  • Range of effects from mild to significant
  • More common and typically more severe in males
  • Often co-occurs with autism, ADHD, anxiety
  • May include physical features and health concerns

Organizations: National Fragile X Foundation

Fetal Alcohol Spectrum Disorders (FASD)

Section titled “Fetal Alcohol Spectrum Disorders (FASD)”

Range of effects from prenatal alcohol exposure.

Understanding FASD:

  • May include intellectual disability, learning differences, behavioral challenges
  • Physical features may or may not be present
  • Often underdiagnosed
  • People with FASD can and do live successful lives with appropriate support

Important note: Stigma around FASD often harms both individuals with FASD and birth mothers. Focus on support, not blame.

Prader-Willi Syndrome

Section titled “Prader-Willi Syndrome”

Genetic condition affecting multiple systems.

Understanding Prader-Willi:

  • Intellectual disability (variable)
  • Distinctive behavioral characteristics including intense food focus
  • Requires specific environmental supports
  • People with PWS can live fulfilling lives with appropriate support

Organizations: Prader-Willi Syndrome Association

Williams Syndrome

Section titled “Williams Syndrome”

Genetic condition causing developmental and medical effects.

Understanding Williams:

  • Often includes intellectual disability
  • Distinctive personality traits (very social, musical interests common)
  • Associated health conditions (heart, kidneys)
  • Strong verbal abilities common

Organizations: Williams Syndrome Association

Other Conditions

Section titled “Other Conditions”

Many other conditions may involve intellectual or developmental disability, including: Rett syndrome, Angelman syndrome, some forms of epilepsy, effects of brain injury, and many rare genetic conditions.

If your condition isn’t listed: The general guidance on this page still applies. Consider contributing information.

Where Are You?

Section titled “Where Are You?”

United States

Section titled “United States”

Services systems:

  • State developmental disability agencies (every state has one)
  • Medicaid waiver programs: Home and community-based services
  • Vocational rehabilitation: Employment support
  • Centers for Independent Living: Peer-based support

Rights and protections:

  • ADA: Prohibits discrimination
  • Olmstead decision: Right to community living
  • IDEA: Educational rights
  • Section 504: Accommodations

Benefits:

  • SSI: Income for people with disabilities who haven’t worked
  • SSDI: For those who have worked (or SSDI on parent’s record in some cases)
  • Medicaid: Healthcare coverage
  • ABLE Accounts: Tax-advantaged savings
  • State supplemental benefits vary

Waiting lists: Many states have long waiting lists for services. Advocacy often needed.

Organizations (self-advocate led):

  • Self Advocates Becoming Empowered (SABE)
  • The Arc (chapters in most areas; many have self-advocacy groups)
  • Autistic Self Advocacy Network (ASAN)
  • State developmental disability councils

Canada

Section titled “Canada”

Services:

  • Provincial developmental services systems
  • Community living organizations
  • Passport Program (Ontario) and similar provincial programs
  • Supported living and employment programs

Benefits:

  • Provincial disability assistance programs
  • Canada Pension Plan Disability (for some)
  • Tax credits
  • See Canada Benefits

Organizations:

  • People First of Canada — self-advocacy
  • Inclusion Canada (formerly CACL)
  • Provincial People First chapters

United Kingdom

Section titled “United Kingdom”

Services:

  • Adult social care through local authorities
  • Personal budgets and direct payments
  • Supported living options
  • Day services and community participation

Rights:

  • Mental Capacity Act: Presumption of capacity; supported decision-making
  • Care Act: Assessment and eligibility for services
  • Equality Act: Disability discrimination protection

Benefits:

  • Personal Independence Payment (PIP)
  • Universal Credit or Employment and Support Allowance
  • Housing benefits
  • See UK Benefits

Organizations:

  • People First groups across UK — self-advocacy
  • Mencap — large charity (some self-advocacy involvement)
  • Inclusion London
  • Learning Disability England

Australia

Section titled “Australia”

NDIS:

  • National Disability Insurance Scheme covers many supports
  • Includes support coordination, therapy, supported living, employment support
  • Plan management options: self-managed, plan-managed, or NDIA-managed
  • See Australia Benefits

Organizations:

  • Inclusion Australia
  • People with Disability Australia (PWDA)
  • State-based self-advocacy organizations

Other Countries

Section titled “Other Countries”

UN CRPD relevant articles:

  • Article 12: Equal recognition before the law (supported decision-making)
  • Article 19: Living independently in community
  • Article 24: Inclusive education
  • Article 27: Work and employment

Many countries are working to move away from institutions toward community living. Progress varies significantly.

Inclusion International: Global network of organizations for people with intellectual disabilities.

See International Rights.

Autonomy and Decision-Making

Section titled “Autonomy and Decision-Making”

The Right to Make Choices

Section titled “The Right to Make Choices”

People with intellectual and developmental disabilities have the right to make decisions about their own lives: where to live, how to spend time, who to spend time with, what to eat, what to do for work, whether to have relationships.

Supported decision-making: Rather than taking decisions away (guardianship), supported decision-making helps people make their own choices with assistance. This approach is increasingly recognized as the best practice.

Guardianship/Conservatorship:

  • Courts can remove decision-making rights — this is serious and should be last resort
  • Limited guardianship (for specific areas only) preferred over full guardianship when any guardianship is needed
  • Alternatives to guardianship should always be considered first
  • Supported decision-making, powers of attorney, representative payees can often provide needed support without removing rights

Presuming Competence

Section titled “Presuming Competence”

Presume competence means starting from the assumption that people understand and can participate, then providing supports — rather than assuming incompetence.

This applies to:

  • Communication (assume people understand even if they don’t speak)
  • Education (assume people can learn)
  • Decision-making (assume people have preferences and can make choices)
  • Employment (assume people can work with appropriate support)

Communication

Section titled “Communication”

Many Ways to Communicate

Section titled “Many Ways to Communicate”

Not everyone uses spoken language. That doesn’t mean they can’t communicate.

Augmentative and Alternative Communication (AAC):

  • Symbol boards and books
  • Sign language or modified signs
  • Speech-generating devices
  • Apps on tablets and phones
  • Any combination that works

Key principles:

  • Behavior is communication
  • Everyone deserves access to communication
  • AAC should be available always, not just in therapy
  • Assume people have things to say

See Communication Access & AAC.

Plain Language

Section titled “Plain Language”

Plain language makes information accessible:

  • Simple, clear sentences
  • Common words
  • Organized logically
  • Visual supports when helpful
  • Key points highlighted

Plain language benefits everyone, not just people with IDD.

Education

Section titled “Education”

Rights to Inclusive Education

Section titled “Rights to Inclusive Education”

Inclusion means learning alongside peers without disabilities, with appropriate supports — not segregated “special” classes.

In the US:

  • IDEA requires free appropriate public education
  • Least Restrictive Environment (LRE) principle favors inclusion
  • IEPs (Individualized Education Programs) specify supports
  • Transition planning for post-school life

Benefits of inclusion:

  • Higher academic achievement
  • Better social outcomes
  • Higher expectations lead to greater achievement
  • Benefits all students, not just those with disabilities

Challenges:

  • Many schools still segregate students
  • Inclusion requires adequate support
  • Advocacy often needed to secure appropriate services

See K-12 Education, Early Intervention, Transition to Adulthood.

Employment

Section titled “Employment”

The Right to Work

Section titled “The Right to Work”

People with IDD have the right to work in competitive integrated employment — real jobs, real wages, real workplaces.

Types of employment:

  • Competitive integrated employment: Jobs in the community at minimum wage or higher
  • Customized employment: Jobs created based on individual strengths and employer needs
  • Supported employment: Jobs with ongoing support from job coaches
  • Self-employment: Running one’s own business

Sheltered workshops and subminimum wage:

  • Some programs pay below minimum wage under Section 14(c) certificates (US)
  • Self-advocates and disability organizations are working to end this practice
  • “Real work for real wages” is the goal
  • Transition to competitive employment is possible

Getting support:

  • Vocational rehabilitation agencies
  • Supported employment providers
  • Customized employment specialists
  • State developmental disability agencies

See Job Searching with a Disability, Supported Employment & Voc Rehab, Workplace Accommodations.

Living in Community

Section titled “Living in Community”

The Right to Community Living

Section titled “The Right to Community Living”

Olmstead (US Supreme Court, 1999): Unjustified institutionalization is discrimination. People have the right to live in the community.

Community living options:

  • Own home or apartment (with or without support)
  • Living with family
  • Shared living arrangements
  • Supported living programs
  • Host home/family care

What community living looks like:

  • Choosing where to live and with whom
  • Control over daily schedule
  • Making decisions about your life
  • Having relationships
  • Being part of neighborhood and community

What it’s NOT:

  • Group homes with institutional rules (though some group homes are better than others)
  • Being isolated
  • Having no choice or control

See Housing & Independent Living, Independent Living Philosophy, Group Homes & Institutions.

Healthcare

Section titled “Healthcare”

Access to Quality Healthcare

Section titled “Access to Quality Healthcare”

People with IDD face significant healthcare disparities:

  • Shorter life expectancy
  • Preventable conditions going untreated
  • Communication barriers in healthcare settings
  • Diagnostic overshadowing (symptoms attributed to disability, not investigated)
  • Lack of provider training on IDD

Advocating for good healthcare:

  • Bring support person if helpful
  • Use communication tools if needed
  • Request longer appointments
  • Ask for plain language explanations
  • Don’t accept “it’s just part of your disability” without investigation
  • Know that people with IDD deserve full healthcare, not just disability-related care

Finding providers:

  • Some areas have specialized clinics for adults with developmental disabilities
  • University medical centers may have more experience
  • Ask other families and self-advocates for recommendations

See Accessible Healthcare, Healthcare Rights.

Relationships, Sexuality, and Parenting

Section titled “Relationships, Sexuality, and Parenting”

The Right to Relationships

Section titled “The Right to Relationships”

People with IDD have the same rights to relationships, sexuality, and parenting as anyone else.

Relationships:

  • Friendships, dating, marriage — all are possible and meaningful
  • Support may be needed to meet people and navigate relationships
  • Isolation is a significant problem — building social connections matters

Sexuality:

  • People with IDD are sexual beings with the right to sexual expression
  • Sex education must be accessible and appropriate
  • Consent education is important (both understanding consent and recognizing abuse)
  • Support for healthy relationships, not prevention of all relationships

Parenting:

  • Parents with IDD can be successful parents
  • May need accessible parenting information and support
  • Child welfare system disproportionately removes children from parents with disabilities
  • Discrimination in custody and adoption is illegal but happens

See Dating & Relationships, Parenting with a Disability, Sexuality & Reproductive Health.

Safety and Abuse Prevention

Section titled “Safety and Abuse Prevention”

Higher Risk, Less Protection

Section titled “Higher Risk, Less Protection”

People with IDD experience abuse at much higher rates than general population:

  • Physical abuse
  • Sexual abuse
  • Financial exploitation
  • Neglect
  • Emotional abuse
  • Staff-to-resident abuse in residential settings

Reducing risk:

  • Education about abuse, consent, and rights
  • Multiple trusted people to report to
  • Independent oversight of group settings
  • Community living (isolation increases risk)
  • Self-advocacy skills
  • Reporting mechanisms that work

If you’re experiencing abuse:

  • Tell someone you trust
  • Contact disability rights organization
  • Adult Protective Services (in US)
  • Police if appropriate
  • See Abuse, Neglect & Exploitation

Intersectionality

Section titled “Intersectionality”

People with IDD Are Diverse

Section titled “People with IDD Are Diverse”

Race and IDD:

  • BIPOC people with IDD face compounded discrimination
  • Disparities in diagnosis, services, and outcomes
  • Criminal justice system disproportionately harms BIPOC people with IDD

Gender and IDD:

  • Women with IDD face higher rates of abuse
  • Reproductive rights have been violated (forced sterilization)
  • Gender identity and expression are rights for people with IDD too

LGBTQ+ and IDD:

  • LGBTQ+ people with IDD exist and deserve support
  • Some people with IDD are questioning or exploring identity
  • Access to affirming support may be limited

Poverty and IDD:

  • Poverty is common due to employment discrimination and low benefits
  • Intersects with housing instability, food insecurity
  • Benefit rules often trap people in poverty

See Intersectionality section.

For Families

Section titled “For Families”

Supporting Family Members with IDD

Section titled “Supporting Family Members with IDD”

If your family member is a child:

  • Presume competence — start with high expectations
  • Include them in community activities
  • Provide communication access
  • Begin self-advocacy education early
  • Plan for transition to adulthood (start by age 14-16)
  • Connect with other families AND with self-advocates

If your family member is an adult:

  • Respect their autonomy and choices
  • Don’t speak for them when they can speak for themselves
  • Support their relationships and independence
  • Learn about supported decision-making alternatives to guardianship
  • Step back when appropriate

For all families:

  • Listen to self-advocates
  • Examine your own assumptions about what’s possible
  • Advocate for community inclusion, not separate “special” programs
  • Take care of yourself too

See Parents of Disabled Children, Caregiving.

Who’s Organizing

Section titled “Who’s Organizing”

The self-advocacy movement has transformed the lives of people with IDD:

History:

  • People First (started 1974 in Oregon): “We are people first, our disabilities are second”
  • Self-advocates have fought to close institutions, end subminimum wage, gain voting rights
  • Increasingly visible leadership in disability rights movement

Current organizing:

  • Closing remaining institutions
  • Ending subminimum wage
  • Fighting for community services funding
  • Self-advocates in leadership positions
  • Inclusive education
  • Employment First policies

Self-Advocates Becoming Empowered (SABE) motto: “Nothing About Us Without Us”

See History of Disability Rights, Advocacy & Self-Advocacy, Get Involved.

Section titled “Related Pages”

Contribute to This Page

Section titled “Contribute to This Page”

Have lived experience or expertise that could strengthen this page? We especially welcome perspectives on models not well represented here, including those from the Global South and Indigenous communities.

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This page centers disabled people’s expertise and is informed by disabled-led organizing globally. For questions or to suggest additions, see How to Contribute.