The Arc is and always has been about people – people with intellectual and developmental disabilities, parents, friends, family and professionals. In 1952, a group of concerned families and their friends formed an organization they called, “Family and Friends of the Mentally Retarded”. In 1953 they joined the National Association for Retarded Children, then Citizens, and became a local chapter. This movement grew and is now known as The Arc, no longer an acronym by eliminating the word “Retarded”. The Arc Muskegon continues to be proudly affiliated with the state and national organization. There are 780 local chapters, with 30 of them in the state of Michigan.

The Arc is a membership organization with a collective membership of 140,000 from across the country. The Arc is the largest grassroots organization advocating for people with intellectual and developmental disabilities and their families. The Arc Muskegon is a proud affiliated chapter of The Arc Michigan and The Arc of the United States.


Developmental disability Defined

Developmental disabilities are a class of disabling conditions that usually originate before birth or shortly after and prior to age 22 and will continue through the course of a person’s life. An intellectual/cognitive disability (previously known as mental retardation) is a developmental disability at which a person’s rate and degree of intelligence is lower than society as a whole. Most people – 87% have a mild intellectual disability. This diagnosis needs to occur by the age of 18 years old.

There are approximately 7.3 million Americans (Source: The Arc US) with an intellectual or developmental disability or one in nine families. Causes can include:

  • genetics
  • trauma at birth
  • poor nutrition
  • substance use
  • lead poisoning
  • accidents
  • environmental factors
  • many causes unknown

Examples of developmental disabilities can include:

  • Autism
  • Down syndrome
  • Cerebral Palsy
  • Fetal Alcohol spectrum disorder
  • Spina Bifida

Intellectual disability Defined

An intellectual disability is a below-average cognitive ability with three (3) characteristics:

  • Intelligent quotient (IQ) is between 70-75

  • Significant limitations in adaptive behaviors (ability to adapt and carry on everyday life activities such as self care, socializing, communicating, etc..)

  • The onset of the disability occurs before age 18