An indirect examination of the function of problem behavior associated with fragile X syndrome and Smith-Magenis syndrome.

Jackson et al. (2012) gave the Questions About Behavioral Function (QABF) to caregivers of people with fragile X syndrome (FXS) and Smith-Magenis syndrome (SMS).

They wanted to see if the two syndromes show different behavior functions.

The team compared the QABF scores to a general intellectual disability group.

SMS profiles pointed to pain or discomfort as a big reason for problem behavior.

FXS profiles showed less attention-maintained behavior than the general IDD group.

In short, the same checklist painted different pictures for each syndrome.

Logan et al. (2000) built the QABF and showed it is quick and psychometrically sound. Jackson et al. (2012) extend that work by proving the tool can also flag syndrome-specific functions.

Nicholson et al. (2006) warned that QABF inter-rater reliability is only modest for low-rate behaviors. Their caution still applies—use direct observation or a full FA to confirm pain signals in SMS.

Hardiman et al. (2018) later pooled FXS studies and found challenging behaviors are common. Paul’s finding that attention functions are lower in FXS helps explain why standard attention-based interventions may falter with this group.

If you assess a client with SMS, score the QABF pain items first and talk to the doctor about hidden medical issues. If the client has FXS, do not assume attention is the main pay-off—look instead for escape or sensory functions. Match your treatment to the profile and you will avoid wasting time on the wrong function.