Who we are – and what we do?

IASSIDD was born out of three international congresses held in Europe between 1960 and 1963. The first, held in London in 1960, was titled Observation of World Mental Health Year. This event was sponsored by the Royal Medico-Psychological Association, The Royal Society of Medicine, the British Psychological Society, in cooperation with the National Association of Mental Health and (the former) American Association on Mental Deficiency. A second congress was held in Vienna in 1961 and a third in Copenhagen in 1964. The International Association was duly formalized at the 1964 Congress, with a constitution published in the American Journal of Mental Deficiency (1965, 69 599) and the Journal of Mental Deficiency Research (1965, 9, 150).

As an international organization, IASSIDD promotes the scientific study of intellectual disabilities and related developmental disabilities and of conditions of persons with these disabilities and their families. IASSIDD defines Intellectual disability as a significant intellectual deficit present from birth, or which originates at an early age or during the developmental period.


A. D. B. CLARKE Department of Psychology,
The University of Hull, Hull England
Journal of Intellectual Deficiency Research, 1991, 35, 1 12

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The Past, the Present and the Future

Trevor R. Parmenter, Ph.D.
University of Sydney
President, IASSID, 1996-2000

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Read More about IASSIDD



Members meet periodically as the Assembly of Members. At least one regular business meeting of the Assembly is held in connection with each World Congress of the Association. The Assembly may also meet upon call of the President or on petition of at least 1/3 of the subscribing members.


The Council is the responsible organ of the Assembly to manage the affairs of the Association

during the interim between meetings of the Assembly. The Council has and exercises all the authority and duties of the Assembly except that authority specifically reserved to the Assembly.


The elected Officers of the Association are the President, the President-Elect, the Secretary and the Treasurer who are elected by the Assembly, following approval by Council. In addition, the President can appoint Vice-Presidents from the members of Council.

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IASSIDD Activities

What Activities Does IASSIDD Sponsor?

The Association furthers its purpose by undertaking the following activities:

  • Serving as a medium for deliberation, for exchange of ideas, knowledge, skills and experience and for compilation and dissemination of information.
  • Organizing international and regional congresses, conferences and seminars.
  • Encouraging research in the field of intellectual and developmental disability, including causes, prevention, diagnosis, evaluation, therapy, management, education and social habilitation of persons with an intellectual or developmental disability and their families.
  • Producing and distributing publications on the scientific study of intellectual and developmental disabilities and of the care of such persons.
  • Fostering, encouraging and promoting membership in the various professional disciplines in national organizations concerned with the scientific study of intellectual and developmental disability.
  • Co-operating with the other organization directly or closely related with the scientific study of intellectual and developmental disabilities.

IASSIDD World Congresses

First and foremost IASSIDD sponsors international congresses, now held once every four years. These international meetings provide an exciting opportunity for presenting recent findings as well as keynote addresses about major advances in the biological, behavioral, and social sciences related to intellectual disabilities. These advances are also addressed in presentations concerned with progress in the provision of services and supports for persons with intellectual disabilities. The most recent Congress was held in Halifax, Nova Scotia, Canada in 2012.

  • A full listing of all IASSIDD World Congresses can be found here

Affiliated Journals

In 1995, IASSIDD became a co-sponsor of the Journal of Intellectual Disability Research (JIDR). JIDR is published monthly by Wiley-Blackwell on behalf of MENCAP and in association with IASSIDD. The journal is interdisciplinary as well as international in its scope and invites submission of empirical research and integrative review articles from IASSIDD members. It is peer-reviewed and readily available in major libraries and universities throughout the world. IASSIDD individual members may purchase a subscription to JIDR at a reduced rate.

IASSIDD also sponsors free or reduced rate subscriptions to JIDR for countries and individuals when funds for acquisition of journals are severely limited. Members of IASSIDD are nominated to serve on the international editorial board. In addition, JIDR prints a special “news” section to keep members informed about activities related to IASSIDD.

Sponsorship of Special Interest Research Groups (SIRGs)

Special Interest Research Groups provide a unique opportunity for researchers from diverse countries and disciplines to engage in a more active exchange about key issues and findings in specific scientific areas to explore opportunities for international collaboration, and to sponsor special events and meetings.

Any member of IASSIDD may join a SIRG or may propose the establishment of a new SIRG. There are 10 Sirgs. For more information about these, go to https://www.iassidd.org/sirgs

Participation in National and Regional Scientific Meetings

IASSIDD co-sponsors many regional and national meetings related to the Association’s mission. In the past, IASSIDD has co-sponsored scientific meetings in Hong Kong, Italy, Ireland, Austria, South Africa, Switzerland,the Netherlands, Singapore and Great Britain. IASSIDD seeks to provide active support for international exchanges, especially during the years between the World Congresses, in the form of sponsored symposia and presentations by IASSIDD elected officers, councilors, and individual members.

Public and Research Policy Initiatives

IASSIDD works closely with various international and national organizations in policy activities to further understanding and research related to intellectual disabilities. It works in partnership with the Inclusion International (formerly called the Intellectual League of Societies for Persons with Mental Handicap), the United Nations, the World Health Organization, and many international groups concerned with the well-being of individuals and families affected by intellectual disabilities and other developmental disabilities. Policy activities are designed to increase research opportunities, the dissemination of research findings, and the translation of scientific advances into more effective intervention practices and prevention efforts.


Awards and Recognition

IASSIDD provides awards for travel scholarships for promising young scientists. Its Stevens-Shapiro Memorial Fellowship awards were established in 1988 in order to encourage participation by outstanding young scientists in IASSIDD international meetings. This award is open to early-career researchers who are actively involved in the field of intellectual disabilities.

IASSIDD also provides awards for major scientific and humanitarian contributions to the field. It confers its highest awards for contributions to the field of intellectual disability research and service once every four years. The categories for awards include: Distinguished Achievement Award -Research, Distinguished Achievement Award – Scientific Literature, and the Distinguished Service Citation. The recipients are honored at a special event at the World Congress. Many of the recipients have played leadership roles in IASSIDD and have presented findings at the World Congresses.

International Association for the Scientific Study of Intellectual and Developmental Disabilities (IASSIDD) 

The International Association for the Scientific Study of Intellectual and Developmental Disabilities (IASSIDD) is the first and only world-wide group dedicated to the scientific study of intellectual disability.

Founded in 1964 as the International Association for the Scientific Study of Mental Deficiency, IASSIDD is an international, interdisciplinary and scientific non-governmental organization which promotes worldwide research and exchange of information on intellectual disabilities.


Please contact the IASSIDD international office for questions about joining IASSIDD, renewing your membership or general questions.
© 2018 International Association for the Scientific Study of Intellectual and Developmental Disabilities (IASSIDD)