special education teachers and daycamps for children with disabilities, all at a time when such training and programs were almost nonexistent. the segregation of people with developmental disabilities was not widely questioned by academics or policy-makers until the 1969 publication of wolf wolfensberger's seminal work "the origin and nature of our institutional models", drawing on some of the ideas proposed by s. g. howe 100 years earlier. this book posited that society characterizes people with disabilities as deviant, sub-human and burdens of charity, resulting in the adoption of that "deviant" role. wolfensberger argued that this dehumanization, and the segregated institutions that result from it, ignored the potential productive contributions that all people can make to society. he pushed for a shift in policy and practice that recognized the human needs of those with intellectual disability and provided the same basic human rights as for the rest of the population. the publication of this book may be regarded as the first move towards the widespread adoption of the social model of disability in regard to these types of disabilities, and was the impetus for the development of government strategies for desegregation. successful lawsuits against governments and increasing awareness of human rights and self-advocacy also contributed to this process, resulting in the passing in the u.s. of the civil rights of institutionalized persons act in 1980. from the 1960s to the present, most states have moved towards the elimination of segregated institutions. normalization and deinstitutionalization are dominant. along with the work of wolfensberger and others including gunnar and rosemary dybwad, a number of scandalous revelations around the horrific conditions within state institutions created public outrage that led to change to a more community-based method of providing services. by the mid-1970s, most governments had committed to de-institutionalization and had started preparing for the wholesale movement of people into the general community, in line with the principles of normalization. in most countries, this was essentially complete by the late 1990s, although the debate over whether or not to close institutions persists in some states, including massachusetts. in the past, lead poisoning and infectious diseases were significant causes of intellectual disability. some causes of intellectual disability are decreasing, as medical advances, such as vaccination, increase. other causes are increasing as a proportion of cases, perhaps due to rising maternal age, which is associated with several syndromic forms of intellectual disability. along with the changes in terminology, and the downward drift in acceptability of the old terms, institutions of all kinds have had to repeatedly change their names. this affects the names of schools, hospitals, societies, government departments, and academic journals. for example, the midlands institute of mental sub-normality became the british institute of mental handicap and is now the british institute of learning disability. this phenomenon is shared with mental health and motor disabilities, and seen to a lesser degree in sensory disabilities. terminology over the past two decades, the term intellectual disability has become preferred by most advocates and researchers in most english-speaking countries. in a 2012 survey of 101 canadian healthcare professionals, 78% said they would use the term developmental delay with parents over intellectual disability (8%). expressions like developmentally disabled, special, special needs, or challenged are sometimes used, but have been criticized for "reinforc the idea that people cannot deal honestly with their disabilities". the term mental retardation, which stemmed from the understanding that such conditions arose as a result of delays or retardation of a child's natural development, was used in the american psychiatric association's dsm-iv (1994) and in the world health organization's icd-10 (codes f70–f79). in the next revision, icd-11, it was replaced by the term "disorders of intellectual development" (codes 6a00–6a04; 6a00.z for the "unspecified" diagnosis code). the term "intellectual disability (intellectual developmental disorder)" is used in the dsm-5 (2013). the term "mental retardation" is still used in some professional settings such as governmental aid programs or health insurance paperwork, where "mental retardation" is specifically covered but "intellectual disability" is not. historical terms for intellectual disability eventually become perceived as an insult, in a process commonly known as the euphemism treadmill. the terms mental retardation and mentally retarded became popular in the middle of the 20th century to replace the previous set of terms, which included "imbecile", "idiot", "feeble-minded", and "moron", among others, and are now considered offensive. by the end of the 20th century, retardation and retard become widely seen as disparaging, politically incorrect, and in need of replacement. usage has changed over the years and differed from country to country. for example, mental retardation in some contexts covers the whole field, but it previously applied to people with milder impairments. feeble-minded used to mean mild impairments in the uk, and once applied in the us to the whole field. "borderline intellectual functioning" is not currently defined, but the term may be used to apply to people with iqs in the 70s. people with iqs of 70 to 85 used to be eligible for special consideration in the us public education system on grounds of intellectual disability. united states special olympics usa team in july 2019 in north america, intellectual disability is subsumed into the broader term developmental disability, which also includes epilepsy, autism, cerebral palsy, and other disorders that develop during the developmental period (birth to age 18). because service provision is tied to the designation "developmental disability", it is used by many parents, direct support professionals, and physicians. in the united states, however, in school-based settings, the more specific term mental retardation or, more recently (and preferably), intellectual disability, is still typically used, and is one of 13 categories of disability under which children may be identified for special education services under public law 108–446. the phrase intellectual disability is increasingly being used as a synonym for people with significantly below-average cognitive ability. these terms are sometimes used as a means of separating general intellectual limitations from specific, limited deficits as well as indicating that it is not an emotional or psychological disability. it is not specific to congenital disorders such as down syndrome. the american association on mental retardation changed its name to the american association on intellectual and developmental disabilities (aaidd) in 2007, and soon thereafter changed the names of its scholarly journals to reflect the term "intellectual disability". in 2010, the aaidd released its 11th edition of its terminology and classification manual, which also used the term intellectual disability. united kingdom in the uk, mental handicap had become the common medical term, replacing mental subnormality in scotland and mental deficiency in england and wales, until stephen dorrell, secretary of state for health for the united kingdom from 1995 to 1997, changed the nhs's designation to learning disability. the new term is not yet widely understood, and is often taken to refer to problems affecting schoolwork (the american usage), which are known in the uk as "learning difficulties". british social workers may use "learning difficulty" to refer to both people with intellectual disability and those with conditions such as dyslexia. in education, "learning difficulties" is applied to a wide range of conditions: "specific learning difficulty" may refer to dyslexia, dyscalculia or developmental coordination disorder, while "moderate learning difficulties", "severe learning difficulties" and "profound learning difficulties" refer to more significant impairments. in england and wales between 1983 and 2008, the mental health act 1983 defined "mental impairment" and "severe mental impairment" as "a state of arrested or incomplete development of mind which includes significant/severe impairment of intelligence and social functioning and is associated with abnormally aggressive or seriously irresponsible conduct on the part of the person concerned." as behavior was involved, these were not necessarily permanent conditions: they were defined for the purpose of authorizing detention in hospital or guardianship. the term mental impairment was removed from the act in november 2008, but the grounds for detention remained. however, english statute law uses mental impairment elsewhere in a less well-defined manner—e.g. to allow exemption from taxes—implying that intellectual disability without any behavioral problems is what is meant. a bbc poll conducted in the united kingdom came to the conclusion that 'retard' was the most offensive disability-related word. on the reverse side of that, when a contestant on celebrity big brother live used the phrase "walking like a retard", despite complaints from the public and the charity mencap, the communications regulator ofcom did not uphold the complaint saying "it was not used in an offensive context and had been used light-heartedly". it was, however, noted that two previous similar complaints from other shows were upheld. australia in the past, australia has used british and american terms interchangeably, including "mental retardation" and "mental handicap". today, "intellectual disability" is the preferred and more commonly used descriptor. society and culture severely disabled girl in bhutan people with intellectual disabilities are often not seen as full citizens of society. person-centered planning and approaches are seen as methods of addressing the continued labeling and exclusion of socially devalued people, such as people with disabilities, encouraging a focus on the person as someone with capacities and gifts as well as support needs. the self-advocacy movement promotes the right of self-determination and self-direction by people with intellectual disabilities, which means allowing them to make decisions about their own lives. until the middle of the 20th century, people with intellectual disabilities were routinely excluded from public education, or educated away from other typically developing children. compared to peers who were segregated in special schools, students who are mainstreamed or included in regular classrooms report similar levels of stigma and social self-conception, but more ambitious plans for employment. as adults, they may live independently, with family members, or in different types of institutions organized to support people with disabilities. about 8% currently live in an institution or a group home. in the united states, the average lifetime cost of a person with an intellectual disability amounts to $223,000 per person, in 2003 us dollars, for direct costs such as medical and educational expenses. the indirect costs were estimated at $771,000, due to shorter lifespans and lower than average economic productivity. the total direct and indirect costs, which amount to a little more than a million dollars, are slightly more than the economic costs associated with cerebral palsy, and double that associated with serious vision or hearing impairments. of the costs, about 14% is due to increased medical expenses (not including what is normally incurred by the typical person), and 10% is due to direct non-medical expenses, such as the excess cost of special education compared to standard schooling. the largest amount, 76%, is indirect costs accounting for reduced productivity and shortened lifespans. some expenses, such as ongoing costs to family caregivers or the extra costs associated with living in a group home, were excluded from this calculation. human rights and legal status the law treats person with intellectual disabilities differently than those without intellectual disabilities. their human rights and freedoms, including the right to vote, the right to conduct business, enter into a contract, enter into marriage, right to education, are often limited. the courts have upheld some of these limitations and found discrimination in others. the un convention on the rights of persons with disabilities, which sets minimum standards for the rights of persons with disabilities, has been ratified by more than 180 countries. in several u.s. states, and several european union states, persons with intellectual disabilities are disenfranchised. the european court of human rights ruled in alajos kiss v. hungary (2010) that hungary cannot restrict voting rights only on the basis of guardianship due to a psychosocial disability. health disparities people with intellectual disabilities are usually at a higher risk of living with complex health conditions such as epilepsy and neurological disorders, gastrointestinal disorders, and behavioral and psychiatric problems compared to people without disabilities. adults also have a higher prevalence of poor social determinants of health, behavioral risk factors, depression, diabetes, and poor or fair health status than adults without intellectual disability. in the united kingdom people with intellectual disability live on average 16 years less than the general population. some of the barriers that exist for people with id accessing quality healthcare include: communication challenges, service eligibility, lack of training for healthcare providers, diagnostic overshadowing, and absence of targeted health promotion services. key recommendations from the cdc for improving the