3.6: Causes of Learning Disabilities

Among students receiving special education services, 33% are identified as having a specific learning disability, the most common category of disability (National Center for Education Statistics, 2022). However, the number of students identified as having a specific learning disability has decreased over time. This may be due to better mechanisms for identifying students with learning disabilities and other categories of disabilities (e.g., RTI/MTSS), as well as a focus on early childhood interventions (Cortiella & Horowitz, 2014; Lerner & Johns, 2015).

In 2022, 42% of students who received special education services for specific learning disabilities were female, and 31% were male (NCES, 2022). This contrasts with the historical trend of males as the predominant gender identified with learning disabilities (Cortiella & Horowitz, 2014). Changes in this trend may be due to reduced bias regarding special education referrals for male students.

Causes of Learning Disabilities

Researchers do not know all the possible causes of learning disabilities, but they have identified risk factors for developing a learning disability. These risk factors are grouped into neurological, genetic, and environmental risk factors and may not apply to all categories of learning disabilities (Smiley et al., 2022).

Neurological Risk Factors

Neurological risk factors for developing a learning disability could include deficits related to brain injury, brain development, or brain structure. For example, there is evidence that individuals with dyslexia have a smaller planum temporale, a section of the temporal lobe of the brain, than individuals without dyslexia (Miller et al., 2003). In addition, researchers have found evidence that indicates distinct patterns of white matter pathways, which are disrupted in math and reading disabilities (Ashkenazi et al., 2013). Research on functional and structural differences in the brains of those with and without learning disabilities indicates support for the existence of neurological risk factors for developing a learning disability (Peterson & Pennington, 2015; Smiley et al., 2022).

Genetic Risk Factors

There is also evidence of genetics as a risk factor for developing a learning disability. Much of this evidence is based on twin studies (Galaburda, 2005). For example, reading disabilities are reported more frequently between identical twins than between fraternal twins (Wadsworth et al., 2000). There is also research that indicates the prevalence of dyscalculia is ten times higher in families of individuals with the disability than would be expected from the general population (Shalev et al., 2001), and genetics is also a risk factor for the development of word recognition problems (Harlaar et al., 2005; Smiley et al., 2022).

Environmental Risk Factors

Environmental factors may also cause learning disabilities. Environmental factors are grouped by those that occur prenatally, perinatally, and postnatally. Prenatal risk factors that cause harm to a fetus include maternal drug use, alcohol consumption, and smoking during pregnancy. For example, mothers who smoke during pregnancy are more likely to have premature babies who are subsequently at risk for developing a learning disability (Dooley, 2009).

Perinatal factors that cause learning disabilities occur at birth or very shortly thereafter. Complications during birth, such as the umbilical cord becoming twisted, could lead to anoxia, the loss of oxygen, a risk factor for developing a learning disability. Brain injuries that occur at birth may also lead to the development of learning disabilities (Zhang, 2007).

Postnatal factors that cause learning disabilities occur after the child is born. For example, medical conditions such as meningitis may contribute to learning disabilities. The ingestion of certain substances, such as lead-based paint, which is known to cause brain injury, may result in the development of a learning disability.

Activity \(\PageIndex{1}\): Preventing Lead Poisoning

Directions: In the United States, lead-based paint is banned, but lead is still found in some water pipes. Learn more about preventing lead poisoning in children by exploring the Centers for Disease Control and Prevention website on Childhood Lead Poisoning Prevention. Consider what populations are at high risk of lead poisoning and how prevention programs work to reduce this risk.

Although cultural and economic factors are excluded as causes from the IDEA definition of learning disabilities, environmental factors such as poor nutrition and adverse childhood experiences are associated with learning disability development (Arends, 2007; Cortiella & Horowitz, 2015; Lacour & Tissington, 2011; Smiley et al., 2022).

Activity \(\PageIndex{2}\): Adverse Childhood Experiences

Directions: Learn more about preventing adverse childhood experiences by exploring the Centers for Disease Control and Prevention website on adverse childhood experiences. Consider the risk factors and protective factors associated with adverse childhood experiences and what teachers and clinicians can do to help students at risk of learning difficulties.

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Cortiella, C., & Horowitz, S.H. (2014). The state of learning disabilities: Facts, trends and emerging issues. National Center for Learning Disabilities.

Lerner, J., & Johns, B. (2015). Learning disabilities and related disabilities (13th ed.). Cengage Learning.

National Center for Education Statistics. (2022). Students with disabilities. Condition of education. U.S. Department of Education, Institute of Education Sciences. Retrieved August 30, 2022, from https://nces.ed.gov/programs/coe/indicator/cgg.

Smiley, L. R., Richards, S.B., & Taylor, R. (2022). Exceptional students: Preparing teachers for the 21st century (4th ed.). McGraw Hill.

Miller, C., Sanchez, J., & Hynd, G. (2003). Neurological correlates of reading disabilities. In H.L. Swanson, K. Harris, & S. Graha, (Eds.), Handbook of learning disabilities (pp. 242–255). Guilford Press.

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Shalev, R., Manor, O., Kerem, B., Ayali, M., Bidici, N., Friedlander, Y., & Gross-Tsur, V. (2001). Developmental dyscalculia is a familiar learning disability. Journal of Learning Disabilities, 34(1), 59–65.

Harlaar, N., Spinath, F., Dale, P., & Plomin, R. (2005). Genetic influences on early word recognition abilities and disabilities: A study of 7-year-old twins. Journal of Child Psychology and Psychiatry, 46(4), 373–384. http://dx.doi.org/10.1111/j.1469-7610.2004.00358.x

Dooley, P. A. (2009). Examining individual and neighborhood-level risk factors for delivering preterm [Doctoral dissertation, University of Cincinnati]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1242748346

Zhang, J. (2007). Perinatal brain injury, visual–motor integration, and poor school performance among low-birth weight survivors in central New Jersey [Doctoral dissertation, University of Pennsylvania]. Dissertations available from ProQuest. AAI3261012. https://repository.upenn.edu/dissertations/AAI3261012

Arends, R. (2007). Learning to teach (7th ed.). McGraw Hill.

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