PIAAC Insights on People with Learning Disabilities in the U.S.: Its Impact on Education

“Have you ever been diagnosed or identified as having a learning disability?” Both household and incarcerated populations were asked this question in the Program for the International Assessment of Adult Competencies (PIAAC). As shown in Figure 1, among the U.S. household population (16-74 years old), 8 percent reported having a learning disability, but among the U.S. incarcerated population, the number was as high as 23 percent. Our overarching question is “What are the commonalities and differences between the household individuals diagnosed with learning disabilities and prisoners with the same condition (i.e., diagnosed with learning disabilities)?”

figure 1

Figure 1: Comparison between percentages of individuals diagnosed with learning disabilities in the U.S. household and the prison populations

What does literature say?

“Adolescents who are placed into juvenile detention centers are disproportionately male minorities with special education disabilities, primarily learning disabilities” (Mallett, 2014, p. 147). Mallett (2014) conducted a case study of juvenile court populations (n = 433) in two midwestern counties and found that youthful offenders with learning disabilities were more likely to be suspended from school, be adjudicated delinquent at younger ages, and be more frequently held in detention centers. He hypothesized that “These outcomes are all risk factors for ongoing delinquent behaviors and, for some, eventual adult criminal court involvement” (p. 147).

As Mallett (2014) admitted, the study had serious limitations that preclude generalizing the above findings, because of the small, local sample, but it certainly points to a concerning issue that warrants further investigation. In another study of offenders with learning disabilities and the criminal justice system (Hayes, 2007), the researcher urged that “We need more information about people with learning disabilities who break the law, so that they get the treatment they need” (p. 146). Our education community needs to know more about individuals with learning disabilities so that school intervention programs may be designed and implemented more effectively.

What is a learning disability (LD)?

A specific learning disability is defined by federal statute as “a disorder in one or more of the basic psychological processes involved in understanding or in using language, spoken or written, that may manifest itself in the imperfect ability to listen, think, speak, read, write, spell, or to do mathematical calculations, including conditions such as perceptual disabilities, brain injury, minimal brain dysfunction, dyslexia, and developmental aphasia” (Title 34: Education, 2014).

How well did individuals with LDs perform on the PIAAC cognitive assessments?

As a large-scale, population-representative study, the PIAAC program assesses adults’ cognitive and workplace skills needed for successful participation in the 21st century society and the global economy. Figure 2 shows that on average, inmates with LDs performed the poorest on the three domains of cognitive assessment (i.e., literacy, numeracy, and problem solving in technology-rich environments). This result is consistent with previous studies on youth offenders with LDs.

figure 2

Figure 2: Comparison of average scores in three domains (literacy, numeracy, and problem solving in technology-rich environments) between people with and without learning disabilities in both household and prison population


For all three skills (i.e., literacy, numeracy, and problem solving in technology-rich environments), the gap between individuals with LDs and those without in the incarcerated population is the same as that in the household population. In other words, people who reported having identified learning disabilities have disadvantages in skills level, regardless of their circumstances. However, inmates with LDs were found to have seriously lower levels in numeracy and problem-solving skills—not in literacy— than household individuals with LDs. In literacy, the difference between household individuals with LDs and inmates with LDs was not statistically significant (Difference = 8.4, p = 0.0525). For numeracy and problem solving, the average scores of inmates with LDs were significantly lower than those of household individuals with LDs (numeracy: Difference = 22.8, p = 0; problem solving: Difference = 22.6, p =0).

In summary, our findings show that numeracy and problem-solving skills seems to be the Achilles’ heel for people with learning disabilities, particularly among the incarcerated population. In the next blog, we will shed more light on individuals, both household and prison, who reported having identified learning disabilities.

(Special thanks to two reviewers of this blog: Ms. Patte Barth, Director of CPE and Dr. Dianne Gut, professor of Ohio University. The major research interests of Dr. Gut include social and academic interventions for students with disabilities in low resource schools, transition planning, mentoring for preservice and inservice teachers, and integrating 21st century skills into curriculum in the content areas.)