Analogical reasoning is a method of processing information that compares the similarities between new and understood concepts, then uses those similarities to gain understanding of the new concept. It is a form of inductive reasoning because it strives to provide understanding of what is likely to be true, rather than deductively proving something as fact. This method can be used by both children and adults as a way to learn new information or as part of a persuasive argument.
The reasoning process begins by a person determining the target domain, or the new idea to be learned or explained. It is then compared to a general matching domain, or an idea that is already well-understood. The two domains must be similar enough to make a valid, substantial comparison. Specific qualities are chosen that belong to the matching domain, then related items are searched for in the target domain to tie the two domains together. For example, food’s effect on the human body can be an analogy to gasoline’s effect on a car because they are both responsible for making entities function correctly.
Analogical reasoning is based on the brain’s ability to form patterns by association. The brain may be able to understand new concepts more easily if they are perceived as being part of a pattern. If a new concept is compared to something the brain already knows, it may be more likely that the brain will store the new information more readily.
The study of the process and effectiveness of analogical reasoning is applied to many fields. Since analogies demonstrate the likelihood of similarities rather than factually proving them, lawyers may use analogical arguments during cases that don’t have a lot of evidence. Such an argument points out a similarity shared by two ideas or objects, then uses that shared similarity to argue that the ideas are likely to have other things in common as well. For example, a lawyer may form an analogy between his or her client and a past court trial for the same offense where the person was found not guilty. Since the circumstances of the charges are similar, a lawyer will argue the outcomes should be similar as well.
The field of science also uses this type of reasoning, but it is used for coming up with new concepts rather than for persuasion. Scientists will often compare a proven scientific process with an unproven one to form hypotheses to base new research on. They may reason that because two processes are similar in one way, they may be more likely to have more things in common.
Psychologists often focus on the cognitive aspects of reasoning. They may perform research to determine how and why the brain retains information through analogies. Psychologists may also study the differences between how children and adults use them.