The following concepts are important to understanding the similarities and contrasts that exist among the many definitions of learning disabilities. Some definitions suggest that learning disabilities exist when a person has uneven patterns of development. Other definitions suggest that learning disabilities are indicated by aptitude-achievement discrepancies. Most definitions specify that the cause for learning disabilities is the result of a problem in the central nervous system. Some definitions suggest that learning disabilities are caused by interference in the neurological processes that make proficient performance possible.
Most definitions imply that learning disabilities can be present at any age.
Most definitions specify that problems understanding spoken or written language can be caused by learning disabilities. Some definitions specify that problems involving social skills, spatial orientation, sensory integration, or motor skills can be manifestations of learning disabilities. Other definitions are worded to eliminate the coexistence of learning disabilities with other disabling conditions. The impacts of learning disabilities may compound with age. While individuals with learning disabilities demonstrate some intellectual strengths, their areas of disability may prevent them from excelling as adults in certain life situations at the same level as their peers.