Leading questions and the eyewitness report

A total of 490 subjects, in four experiments, saw films of complex, fast-moving events, such as automobile accidents or classroom disruptions. The purpose of these experiments was to investigate how the wording of questions asked immediately after an event may influence responses to questions asked considerably later. It is shown that when the initial question contains either true presuppositions (e.g., it postulates the existence of an object that did exist in the scene) or false presuppositions (e.g., postulates the existence of an object that did not exist), the likelihood is increased that subjects will later report having seen the presupposed object. The results suggest that questions asked immediately after an event can introduce new—not necessarily correct—information, which is then added to the memorial representation of the event, thereby causing its reconstruction or alteration.     

Family resemblances: Studies in the internal structure of categories

Six experiments explored the hypothesis that the members of categories which are considered most prototypical are those with most attributes in common with other members of the category and least attributes in common with other categories. In probabilistic terms, the hypothesis is that prototypicality is a function of the total cue validity of the attributes of items. In Experiments 1 and 3, subjects listed attributes for members of semantic categories which had been previously rated for degree of prototypicality. High positive correlations were obtained between those ratings and the extent of distribution of an item's attributes among the other items of the category. In Experiments 2 and 4, subjects listed superordinates of category members and listed attributes of members of contrasting categories. Negative correlations were obtained between prototypicality and superordinates other than the category in question and between prototypicality and an item's possession of attributes possessed by members of contrasting categories. Experiments 5 and 6 used artificial categories and showed that family resemblance within categories and lack of overlap of elements with contrasting categories were correlated with ease of learning, reaction time in identifying an item after learning, and rating of prototypicality of an item. It is argued that family resemblance offers an alternative to criterial features in defining categories.     

“in”, “on”, and “under” revisited

The present study presents evidence that young children's comprehension of the locatives ‘in’, ‘on’, and ‘under’ is, at least in part, contextually determined. Children aged 1;6–3;0 were given tasks with verbal instructions which were either contextually congruent or incongruent. The results were interpreted in terms of the non-linguistic as well as linguistic strategies apparently used to interpret speech. The results and interpretation are in contrast to those of earlier research.     

Recognition memory retention interval and information load

Two experiments were conducted to study the effect of retention interval and information load on short-term recognition memory in retarded subjects. The task consisted of an input trial of 1–15 pictures followed by a test trial of one picture, with the subject having to press different levers to indicate whether the probe picture had been present on the input trial. Retention intervals between input trial and test trial were manipulated over a range of 1–24 sec. Both accuracy and latency of response were measured. Results showed that latency increased and accuracy decreased as a function of both retention interval and number of stimuli. In addition, number of stimuli interacted with retention interval such that accuracy was not affected by retention interval when information input was small, but decreased quite dramatically at longer retention intervals when input was larger. The results were discussed in terms of current memory search models for both normal and retarded subjects.     

The effects of increasing familiarity on infants' reactions to adult strangers

The influence of the presence and novelty of an adult stranger on the reactions of 12-mo-old infants was investigated. Subjects were placed near their mothers in a room containing a new toy and either the same, a different, or no adult stranger for 8 4-min trials. Results indicated that the Same-Adult Group spent more time near the adult, less time near and touching their mothers, and more time near and touching the toys than the Different-Adult Group. These trends emerged as the trials progressed, and evidenced the Same-Adult Group's growing familiarity with the adult. The No-Adult Group spent less time near or touching their mothers and more time near or touching the toys than the Different-Adult Group, but did not differ from the Same-Adult Group on these responses. The findings suggest that fearful or cautious reactions to adult strangers disappear rapidly as the adult becomes familiar and point to the value of studying the process whereby the infant becomes familiar with new people.     

The effects of a memory aid on three types of conservation judgments

Twelve boys and 12 girls at each of 3 ages (4, 5, and 6 years) were tested on three types of conservation judgments (qualitative, quantitative, and equivalence) on both continuous and discontinuous substances. Half of the subjects were provided a memory aid while the other half were not. Conservation ability was determined both with and without verbal justification. The memory aid increased the number of equivalence conservation responses only when verbal justification was not required. The number of subjects conserving on each of the three tasks varied as a function of the scoring criteria used. Type of materials, sex, and age effects were found. The role of transitive inferences and memory in the equivalence conservation task was discussed. Inconsistencies in previous research due to different scoring techniques were noted.