Abstract reasoning is a style of thought based on the skill of abstraction, or considering some aspects of an object but not others. More broadly, abstraction is the ability to think about elements of reality without having real objects in front of you. For example, when you use inductive reasoning to make a prediction about how quickly a given aqueous solution will boil, you are using abstraction, because you are making predictions based on the object's properties, not actually doing a physical experiment. Hearing impairments do not make it impossible for children to think in abstract terms; however, this sensory loss does make it harder for children to learn abstract thinking skills. For example, several studies in the 1950s and 1960s indicated that deaf children do, on average, tend to have less developed abstraction faculties compared to hearing children.
Temporal reasoning is the ability to think in terms of time. Temporal thinking is a type of abstract reasoning in the sense that, to think about blocks of time, you have to think in terms of a construct that cannot be derived from the senses. A 1997 study in the “CAEDHH” journal showed that deaf and hearing-impaired children keep track of time less effectively than hearing children. However, the study concluded that this problem was attributable to a general defect in abstract thinking skills, and not in the hearing-impaired child’s inability to understand the language of time.
Analogical reasoning, the ability to make comparisons, is one of the most important high-level abstract thinking skills. According to psychologist Jean Piaget, children with developmentally normal abstract thinking skills will be capable of basic analogical reasoning by age 12, referred to as the start of Piaget's "formal operational" cognitive stage. A study by Bandurski and Gafkowski in the “Oxford Journal of Deaf Studies and Deaf Education” showed that deaf children develop analogical reasoning skills at around the same age hearing children do, and that deaf children are just as adept at analogical reasoning as hearing children.
Verbal logic is the tool that allows for the expression of abstract reasoning. While verbal logic and abstract reasoning are not the same thing, they tend to develop in tandem. Deaf and hearing-impaired children are capable of expressing verbal logic through sign language and written language. If a deaf child is taught to write at an early enough age, she will show no deficit in her verbal logic abilities. However, many deaf children do not learn to read until later in childhood, and these deaf children, like other late readers, tend to be delayed in their verbal logic skills.