I am not sure if this is exactly what you are asking, but, in analyzing interviews with families with disabled children and adolescents (all types of disability, including intellectual), as well as interviews with the children themselves, in indigenous families in Mexico, we found that various types of inclusion were important. Family inclusion was the first level and very important. It may sound strange to speak of family inclusion, but when a child is in bed or a hammock ALL the time, when the child does not eat with the family, when the child is not even seated near the family when day to day activities take place, then there is no family inclusion. We found that when families included children and adolescents in any activities, even in a limited way such as the child sitting near or next to the rest of the family while family members did things, or the child participating in any way possible, even if the child was near and the family members just talked to the child about what they were doing without any active participation by the child, then the child and their caretaker reported that the child had better quality of life and that the family accepted the child more. This family inclusion (and family acceptance) then sometimes led to greater community inclusion. Community inclusion included things like the disabled child playing with neighboring children (or at the beginning, being present when other children played), going to the store or to other places in the community (often not alone but accompanied by their family members) and also participating in community activities which included cultural activities. School inclusion was also of course extremely important and our qualitative data seemed to indicate that family inclusion and community inclusion were often the first steps or first stages which later led to school inclusion. Nevertheless, school inclusion was not always achieved, but in those children and adolescents who had increased family inclusion and community inclusion, even without school inclusion, their family members and they themselves reported in qualitative interviews that this was very important and pleasurable to them. So, I think any rites of passage children were included in would have a positive impact on them. I hope this helps.

Great answer from Betania.  School inclusion is very powerful if it can be achieved.  If children grow up together then they are much more likely to continue the relationships into the society.  There is a literature review on my website (http://www.include.com.au/resources/) and also see http://www.startingwithjulius.org.au which has some very inspiring stories and ideas.

Perhaps you will get additional fruitful ideas by reading Hart, O. van der (1983): Rituals in psychotherapy - Transition and continuity. New York: Irvington. Interesting examples of what taylor-made rituals can do where standard psychotherapies fail. Only available second-hand with Amazon. Amazon announces it (or did so) as written in Dutch, but actually it is an English translation of "Overgang en bestandiging".

I do indeed thank Bretania, Robert and Peter.  I found three rites of passage in my data. One was in naming customs, where the child was given entry to the family.  The hospital of course requires a name before release.  However my participants all had extravagant systems for giving the nickname for family use, such as phonemic alliteration repeating first letters of all siblings, names of endearment offered by one relative who is emotionally close to the mother and letter mixing where initial letters of mothers and fathers first names or nicknames produce a new word.  Buddhist Monks or spirit doctors were consulted in some cases who assigned names that had auspicious meaning such as ruby eye or lustral water. These were meant to bolster the child's fortune, but may be seen by outsiders observers as stigmatic, which may induce parent/relatives expectations for the child's development, patterns of hyper protection and refusing further education for the child.

I also found that inheritance patterns exclude the sibling with Down Syndrome, prefering that the child stay with the mother throughout her or his life.  As such, independant living and customized employment are not commonly in the parents perview in my current study.

Adjustment to the reality of a child born with DS also had key symbolic moments over the first 2 years.  

Robert:  I note that some of my PhD students will be visiting Curtin University this fall at the School of Occ. Ther.   Our schools signed an MOU in May.  So particular thanks for your input.  Let me review your website for further info.  Regards! DP