Thursday, July 22, 2010

Living the Least Dangerous Assumption

Kate Ahern
Teaching Learners with Multiple Special Needs

Some of the most difficult things we face in our field are those things which are intangible.  One of the most damaging to our students and possible our sense of purpose as educators is that our students must somehow prove themselves, repeatedly, to show they are capable, competent, and are acting with intentionality when they attempt to communicate be it through language, AAC or behavior. We live in a land of prerequisites and accountability, which leaves little room for "The Least Dangerous Assumption"  as pioneered by Anne Donnellan  and clarified by Rossetti and Tashie (2002).  The least dangerous assumption is, of course, the premise that (in the absence of evidence) we believe we not yet found a way to make it so a child or adult with a disability "can" instead of believing he or she "can't".

The issue, sadly, sometimes becomes that making the least dangerous assumption and thus presuming competence uses resources (time, money, energy).  We must come to understand that refusing to presume competence is, in the long run, more costly than making that least dangerous assumption.

Let's take, for example, a child who at age ten is presumed to be functioning at "a 6 month level" in spite of the difficulty of truly measuring the capabilities of an individual who moves only his eyes and tongue, communicates only through moaning vocalization, sleeps most of the school day and does not live in an English speaking home. While it may be true that this individual has significant developmental delays it also may be true that this child does NOT have significant developmental delays. When we choose not to accept the premise of severe cognitive disability and instead begin to form a relationship with the child, build trust in that relationship, respond to eye, tongue and vocalizations as if they are intentional and then introduce assisstive technology we may find that this individual in fact is at grade level. This is a true story and it turned out that little boy was, indeed, not developmentally delayed, and one has to wonder how many stories are out there are there where individuals are capable of so much more than is being presumed of them. Even if it were just that this little boy functioned three, six or 24 months higher developmentally than his initial evaluation suspected it would have been a triumph of "the least dangerous assumption." The child would have been given the gift that presuming competence creates. And what a marvelous gift it is.

How DO we go about living the least dangerous assumption and giving the gifts that presumed competence creates? Here are some ways:
  • Focus on who your students are becoming, not what they are doing
    • It is the process not product
    • Every interaction of the possibility of being the A-HA moment
  • Give the gift of assuming intentionality in communication
    • Because even if you are wrong in your assumption you will teach intentionality by responding as if the action was intentional (pure application of behavior analysis there)
  • See strengths
    • What can they do
    • How can you shape what they can do
    • How can you better understand why they do what they do within the assumption of competence
  • Wait. Then wait more. 
    • Patience makes things possible (allow processing time)
    • Rushing is no path to discovering abilities
  • Puzzle out possibilitiesd
    • Think critically about your students and how to reach them
    • Treat writing evaluations and IEPs as an opportunity to better understand the individual and share that understanding with others
  • Use the right tools for the job
    • Introduce assistive technology (AT)
    • Teach assistive technology
    • Always work towards the next step in using assistive technology (don't be satisfied with cause and effect, keep trying for something more)
  • Ignore the nay-sayers and negative people who see every student action through the lens of the lowest possible level of understanding and imply your presumption of competence is no more than your projection of your wishes for the child
    • You can do no harm by making the least dangerous assumption
    • And you might even change the world
  • Never give up
  • Even when everyone else has
  • Especially when the student has


Donnellan, Anne, (1984)  "The Criterion of the Least Dangerous Assumption" Behavioral Disorders, v9 n2 p141-50 Feb 1984 (print copy not available).

Rossetti, Zach and Tashie, Carol (2002) "Outing the prejudice: Making the least dangerous assumption." The Communicator: Newsletter of the Autism National Committee, 2002.  downloaded from on June 30 2010.

Note: a further discussion of the "Least Dangerous Assumption" concept is Jorgensen, Carol (2005) "The Least Dangerous Assumption: A Challenge to Create a New Paradigm"  Disability Solutions, Vol 6 issue 3 Fall 2005  downloaded from on on June 30 2010.


A version of this essay was originally published at Kate's blog, Teaching Learners With Multiple Special Needs