Assessment & Research

Patterns of intellectual, adaptive and behavioral functioning in individuals with mild mental retardation.

Soenen et al. (2009) · Research in developmental disabilities 2009
★ The Verdict

Mild ID splits into four behavior types, so assess first, then pick targets that fit the profile.

✓ Read this if BCBAs writing assessment plans for teens or adults labeled mild ID.
✗ Skip if Clinicians who only serve severe-profound ID or ASD without ID.

01Research in Context

01

What this study did

Soenen et al. (2009) looked at 73 adults with mild intellectual disability.

They ran a cluster analysis on IQ, daily-living and behavior scores.

The goal was to see if the single label "mild ID" hides different sub-groups.

02

What they found

Four clear behavioral profiles popped out of the numbers.

One group had strong self-help but poor social skills. Another showed the opposite pattern.

The study shows "mild ID" is not one thing; it is at least four.

03

How this fits with other research

Garrison et al. (2025) repeated the idea with youths and found five, not four, profiles. The extra group had high peer problems plus low teacher warmth.

Leonard et al. (2022) used the same math on quality-of-life data. Kids with Down syndrome landed in the top QOL class while kids with Rett landed in the lowest.

Bao et al. (2017) did a near-copy with the SIS-C support-needs scale and again found four classes inside ID plus autism. The pattern keeps holding: one label, many clusters.

04

Why it matters

Stop writing generic "mild ID" goals. Look at the cluster the person falls into.

If social skills lag but self-care is strong, write social goals first.

If the profile shows high support needs across domains, plan for more staff hours.

Use short checklists for peer acceptance, teacher warmth and daily routines. Match your intervention to the subtype, not the broad diagnosis.

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Add a five-minute peer-acceptance and daily-living checklist to your intake; group clients by the four profiles before you write goals.

02At a glance

Intervention
not applicable
Design
other
Sample size
73
Population
intellectual disability
Finding
not reported

03Original abstract

Many researchers have studied the population of individuals with mild mental retardation (MIMR) as if it is a clear entity. Few researchers have investigated potential subtypes within the MIMR population. The purpose of the present study was to investigate which subtypes can be identified on the basis of intellectual, adaptive and behavioral functioning. Seventy-three individuals with MIMR were assessed on measures of intellectual, adaptive and behavioral functioning. An agglomerative hierarchical cluster-analytic technique was used to define potential subgroups with characteristic behavioral patterns. Four subtypes were identified. The behavioral patterns are described and implications for assessment are discussed.

Research in developmental disabilities, 2009 · doi:10.1016/j.ridd.2008.04.003