Assessment & Research

Examining the operant function of challenging behavior in young males with fragile X syndrome: a summary of 12 cases.

Machalicek et al. (2014) · Research in developmental disabilities 2014
★ The Verdict

In fragile X boys, problem behavior is usually kept alive by wanting stuff or wanting out of work, not by wanting looks from adults.

✓ Read this if BCBAs who assess or treat young boys with fragile X syndrome.
✗ Skip if Practitioners working mainly with girls or with older fragile X clients.

01Research in Context

01

What this study did

Machalicek et al. (2014) ran 12 single-case functional analyses on boys with fragile X syndrome. Each boy got the standard test conditions: attention, escape, tangible, and alone. The team watched which condition made the problem behavior spike.

All kids were young males with fragile X. No girls were tested. The goal was to see which function shows up most often in this group.

02

What they found

Tangible and escape topped the list. Attention barely showed up. In most boys, problem behavior jumped when toys were taken away or when work was asked.

The pattern was clear: assume the kid wants a item or a break, not your eye contact.

03

How this fits with other research

Misak et al. (2011) saw the same thing three years earlier in a mixed-sex fragile X sample. Both papers found escape and tangible ruled, attention sat out. The 2014 study extends the 2011 finding by focusing only on boys.

Davis et al. (1994) looked at 152 functional analyses across many diagnoses. They also flagged escape as the top function for self-injury. Wendy et al. match that trend, but add the fragile X lens.

Van der Molen et al. (2010) surveyed parents nationwide. They noted high rates of self-injury in fragile X boys, yet offered no function data. Wendy et al. fill that gap with direct tests, not parent recall.

04

Why it matters

Skip the attention condition first. Start with tangible and escape tests when you assess fragile X boys. You will save time and get faster buy-in for treatment. Pair this finding with the 2011 paper to justify a brief FA that drops attention early.

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Run escape and tangible conditions first in your FA; only add attention if those two flop.

02At a glance

Intervention
functional analysis
Design
single case other
Sample size
12
Population
developmental delay
Finding
positive

03Original abstract

This study used experimental functional analyses to examine the operant function of challenging behaviors exhibited by 12 males (ages 27-51 months) with fragile X syndrome (FXS). Eight children met criteria for negatively reinforced challenging behavior in the form of escape from demands and/or escape from social interactions. Nine children met criteria for positively reinforced challenging behavior in the form of obtaining access to highly preferred items. Attention was identified as a maintaining consequence for three children. The functional analysis was inconclusive for one child. Results suggest that, for young males with FXS, challenging behaviors may more likely be tangibly and escape maintained than attention maintained. Our findings affirm past research suggesting a unique behavioral phenotype for this population.

Research in developmental disabilities, 2014 · doi:10.1016/j.ridd.2014.03.014