The Principle Of Extracting Background Relations In Property Effect Of Inductive Reasoning

Property effect, also called interaction between properties and premise-conclusion matches, is an important psychological effect in inductive reasoning, which suggested that people could base on the background relation (relations between premise and conclusion) property most relevant to. At the same time, previous studies showed that different types of background relation vary in their relative accessibility. Therefore, the first problem of current study concern is tries to examine which kind of background relation people would give priority to, the most accessible or the property most relevant, in inductive reasoning. The second problem of current study concern is which kinds of background relation people would give priority to, the positive or negative relevant.In the first experiment, the triple paradigm was used. In the induction task,64 Chinese undergraduates were told about a novel gene or a novel disease that was true of one category of animals, then they were presented two another animals, each of them was taxonomically, ecologically, or unrelated to the first animal, and asked them to judge which one had the same property between the two animals onset lately under the speeded or delayed condition. Under speeded condition the last two animals presented 1s (delayed conditions 10s); participants were asked to judge as quickly as possible after they disappeared. After this task they were asked to completed a classify task about had been onset projects in induction task. The result reveled that when they were asked to infer the gene property, they tended to select the animal which taxonomically related to the first animal, but when they were asked to infer the disease property, they significantly tend to select the ecologically related animals whether the speeded or delayed condition. And the bias in the classify task can predict the bias of gene property inference, but can't predict the disease inference.The second experiment also consisted of two parts:a property induction task followed by a belief-assessment task, which were all conducted on the computer using E-Prime, too. In the induction task,64 Chinese undergraduates were told about a novel gene or a novel disease that was true of one category of animals, they had to judge whether taxonomically, ecologically, and unrelated animals had the same property or not, under speeded or delayed conditions like the first experiment. After the judgment, they were asked to evaluate the confidence in their judgment from 1 to 7. In the belief-assessment task, participants were shown each item again and asked "Do these animals live in the same habitat?" and "Do these animals belong to the same biological category?", They answered "yes" "no" or "don't know". The result revealed that:(1) Property effect was independent of time pressure, too. The possibility of reasoning (the percent of judged "yes" in the induction task) for gene between taxonomically related animals was greater than for disease in both speeded and delayed conditions, but between ecologically related animals, there was no difference. (2) Time pressure affected the confidence of reasoning, higher in speeded conditions than in delayed conditions. (3) In the speeded conditions, both taxonomical and ecological relatedness beliefs could predict the possibility and confidence of reasoning, but in delayed conditions both beliefs couldn't.These results get from the two experiment above proved that people are firstly extract the background relation property most relevant to then extract those less relevant or un-relevant in inductive reasoning. And when the positive and negative relevant background relations coexist in inductive reasoning, people would give priority to positive relevant background relation.