Blackwell Reference Online

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In their everyday worlds, adults and children are frequently required to “go beyond the information given” and make inferences that are not deductively valid. When there are gaps in our knowledge, we have to reason by induction. Generalizing on the basis of a known example, making an inductive inference from a particular premise, or drawing an analogy are all examples of inductive reasoning at work. Inductive reasoning is ubiquitous in human thinking. Deductive reasoning can also fill gaps in knowledge. In contrast to inductive reasoning, however, in a deductive reasoning problem there is only one logically valid answer. Deductive reasoning is usually measured by the ability to apply deductive logic to known information that is given. For example, if a child is given the two premises “All dogs bark” and “Rex is a dog”, there is only one logical deduction. Rex is a dog, all dogs bark, therefore Rex must also bark. One important difference between inductive and deductive reasoning is that deductive reasoning problems can be solved without (or despite) real-world knowledge. In the above example, a child can make a logical deduction about Rex barking even if “barking” is a totally unfamiliar activity. If the child had been told instead “Rex is a cat. All cats bark. Does Rex bark?”, then the correct deduction would again be that Rex must also bark, even though in the real world cats ... log in or subscribe to read full text