在成人印象形成的過程中，行為者的負向行為往往較正向行為對印象的形成更具影響力，即有所謂的負偏誤。但學齡前的孩子，在延宕的情況下，根據行為對行為者做特質判斷時，卻是正向行為較負向行為具影響力，因此反而有下偏誤。Rholes & Rube (1986) 認為，正偏誤的產生是因為孩子具有人性本善的潛伏理論所致。為了了解此種人性本善的潛伏理論是在印象形成的哪一個階段，導致正偏誤的判斷，本研究以孩子平日常發生的情境為互動刺激，要求個體在三個階段，即1.接受有關行為者的四個一致訊息後2.在接受一致訊息後，延宕一天，還未接受其他刺激前3.接受一致訊息後，在立刻或延宕一天的情況下，接受一個不一致訊息後，對行為者做好、壞內在特質的判斷。研究對象是幼稚園及三年級各位小朋友，操弄的變項是間隔時間（立刻╲延宕）及行為序列（先正後負╲先負後正），另外，故事的呈現上，主角可能是孩子本身或第三者。結果發現：(1)所有孩一致負向訊息的判斷，在延宕一天的情況下，都較立刻情況下的判斷為正。(2)三年級的學童在接受不一致新近訊息後，正向新近訊息對原來負向印象的改變量，較負向新近訊息對原來正向印象的改變量為大。(3)判斷上的正偏誤，當三年級孩子是行為的接受者時現象就不存在。

In impression formation, negative behavior information was found to be much more powerful than positive information in adult judgment. This phenomena is called negative bias. However, when a preschooler made a personal judgment in a delayed situation, the opposite was found. Rholes & Ruble (1986) proposed that this positive bias was caused by a child’s implicit theory. In order to understand the possible stages where the implicit theory caused the positive bias, the present study divided judgment processes into three stages. Subjects made their first judgment after they had received four pieces of consistent information. The second judgment was made rights before they received the fifth inconsistent piece of information. The third judgment was made rights after they received the inconsistent information. Eighty preschooler and eighty third-grade students were tested individually. The three independent variables manipulated were：the time of inconsistent information （immediate/one day delay）, the information sequence （positive before negative/negative before positive）, the role of the subject （receiver/observer）. The results showed that：(1) All children, after they received the consistent information but before they got the inconsistent information, presented a positive bias in a delayed situation. (2) For third grader, the positive recent information was more powerful than the negative one to modify their prior impression. (3) The above positive bias was not found in third graders when their roles were as receivers.