证据顺序和证词可信度对学前末期儿童因果推理的影响

The Influence of Evidence Order and Testimony's Reliability on Preschoolers' Causal Inference

开展两个实验探究证据顺序和证词可信度对学前末期(65～70月龄)儿童因果推理的影响。132名和127名儿童分别参与实验1和实验2。实验1发现证据顺序对儿童因果推理的影响表现为近因效应,证词可信度不影响儿童的推理结果;实验2发现如果强制要求儿童注意证词可信度信息,他们更相信可信证词而非不可信证词,证据顺序对推理结果无影响。研究结果说明学前末期儿童的因果推理受证据顺序和证词可信度的共同影响:在未被要求注意证词可信度时,受制于有限的工作记忆容量,大多数儿童依据最近接收到的证据推断因果关系;如果注意到证词可信度信息,更多儿童依据证词(可信证词条件)或观察结果(不可信证词条件)推断因果关系。

A number of studies focused on how preschoolers make their inference based on the results of observation, the results of experiment, or testimonies from adults. But until recently, the psychological mechanism of the interaction of three kinds of information in children＇s scientific thinking has not been elucidated （Sobel ＆ Kushnir, 2013）. In this study, a research paradigm from Bridgers et al. （2016） was used in two experiments to explore the influence of order in two kinds of evidence： adult＇s testimony and adult＇s experiment, on 5-year-old children＇s causal inference. Children＇s perception of the level of testimony＇s reliability and informant＇s awareness were also analyzed. Experiment l adopted a 2x2 completely randomized experimental design, the independent variables were the testimony＇s reliability （two levels： reliable, unreliable） and the order of evidence （two levels： testimony prior to experiment, experiment prior to testimony）, the dependent variable was the frequency of children＇s choice of candidate cause. Both testimony and experiment were given by a female adult on a laptop respectively. In order to provide conflicting evidences, testimony identified one of two plastic bricks, such as brick A, that almost always makes a machine go, but the result of adult experiment showed that brick B made the machine go better. 132 preschool children （77 boys and 55 girls, mean age： 68.2 months） took part in Experiment 1. All participant completed experimental tests in the reading room, the drawing room or the small library of a kindergarten. The results showed that children chose causes according to testimony in conditions that the experiment preceded the testimony, and according to experiment in conditions that the testimony preceded the experiment, resulting in a recency effect. The main effect of testimony＇s reliability was not significant, which meant that children in 5-year-old were not sensitive to the testimony＇s reliability. Children were not sensitive to informant＇s awareness. Experiment 1 found that children were not sensitive to the testimony＇s reliability, which might be unaware of the information of testimony＇s reliability. Experiment 2 adopted the same experimental design as Experiment 1, but appended a reliability question to the end of testimony. 127 preschool children （70 boys and 57 girls, mean age 69.3 months） took part in experiment 2. The results showed that children in condition of reliable testimony chose causes according to testimony, and according to the result of experiments in conditions of unreliable testimony, but the effect of evidence order were removed. Again, children were not sensitive to informant＇s awareness. It seemed that 5-year-old children gave the same weight to adult＇s testimony and experiments, and the change of evidence order brought a recency effect on children＇s causal inference. However, the recency effect would be eliminated by appending a confidence question to the end of testimony. Even so, future studies should balance the order of different evidences. The main effect of awareness of witness was not significant. The follow-up research should focus on the interaction of independent exploration, ＂observing others＂ experiment and informant testimony on preschool children＇s scientific thinking, on the influence of evidence strength and on how to improve children＇s scientific thinking in preschool＇s curriculum.