Preschoolers' and adults' reliance on object shape and object function for lexical extension.

We investigated the developmental progression of reliance on object function versus object shape to extend novel words. In 3 experiments, 3-year-olds, 5-year-olds, and adults were presented with sets of objects consisting of a target, a same-shape/different-function match, a different-shape/same-function match, and a distracter. In Experiments 1 and 2, function was emphasized during the word learning phase and participants were given direct experience with the functions of target and test objects. In Experiment 3, function was emphasized both during the learning phase and when requesting a referent of the novel labels. Across all 3 experiments, 3- and 5-year-olds focused on shape while adults focused on function when extending the novel words. These results suggest a developmental change in the consideration of shape and function in lexical extension.     

The role of gesture in children's learning to count.

The role of spontaneous gesture was examined in children's counting and in their assessment of counting accuracy. Eighty-five 2-, 3-, and 4-year-olds counted 6 sets of 2-, 4-, and 6-object arrays. In addition, children assessed the counting accuracy of a puppet whose gestures varied as he counted (i.e., gesture matched the number words, gesture mismatched the number words, no gesture at all). Results showed that the correspondence of children's speech and gesture varied systematically across the age groups and that children adhered to the one-to-one correspondence principle in gesture prior to speech. Moreover, children's correspondence of speech and gesture, adherence to the one-to-one principle in gesture, and assessment of the puppet's counting accuracy were related to children's counting accuracy. Findings are discussed in terms of the role that gesture may play in children's understanding of counting.     

The influence of peers on children''s judgments about engaging in behaviors that threaten their safety

Unintentional injuries are the number one cause of death among children beyond one year of age. Many injuries among school-age children happen when they are away from home and in the company of peers. The aim in this study was to examine peer influences on children's judgments about engaging in behaviors that threaten their physical safety. Children were shown pictures depicting play situations which involved different paths of travel, each of which posed different degrees of injury risk. Children were asked to select the path they would take, and to assign a danger rating to reflect their beliefs about the likelihood of injury along this path. A peer-influence session followed, in which a same-sex friend attempted to persuade the child to take another path. Following exposure to the friend's arguments, children made their final decision about a path of travel in each play situation; the peer was not present during this decision and the experimenter present was unaware of the child's initial path choice. A number of other measures were taken in an effort to determine factors that influence children's risk-taking decisions. Results revealed that friends were successful in their persuasion efforts: for two of the three play situations, a significant number of children who initially selected low-risk paths switched to more risky paths. Appraisal of danger related to initial path decisions, but number of hazards identified and injury history did not significantly relate to initial decisions. The implications of these results for our understanding of injury-outcome processes are discussed.     

The representation of nonstructural information in visual memory: Evidence from image combination

Two experiments investigated the differential representation of the figure and ground of a picture in visual short-term and long-term memory. It is known (Hitch, Brandimonte, & Walker, 1995) that subjects find it more difficult to combine mental images of two separately presented pictures in order to identify a novel form when the two pictures are incongruent in color (i.e., when a black-on-white line drawing has to be combined with a white-on-black drawing). In the present experiments, thefigures were depicted in solid form to allow color congruity to be varied independently for figure and ground. Results showed a clear impairment in image combination when the to-be-combined figures were incongruent in color (black-on-gray and white-on-gray) but not when theirgrounds were incongruently colored (gray-on-black and gray-on-white). In this way, image combination was seen to be supported by a representation of the object depicted in the picture rather than by a literal representation of the picture itself (i.e., a pictorial code). In line with previous findings, the same representation was seen to support image combination based on short-term memory (Experiment 1) and long-term memory (Experiment 2), provided that in the latter case verbal recoding was precluded. When verbal recoding was allowed, image combination based on long-term memory was insensitive to color congruity, implying the involvement of a more abstract structural representation.     

Are two heads better than one? Experimental investigations of the social facilitation of memory

The hypothesis that two people collaborating in recall would remember more than a single person was examined in a series of four experiments. All the experiments used variations on the same ‘sequential’ design where, in social conditions, people recalled alone initially and then recalled jointly in pairs: as a control for reminiscence, some people recalled alone on two separate occasions. On the second recall in all of the experiments two people always recalled more than one, but this was simply due to the independent statistical summation of two people's memories: no evidence whatsoever was found for the pairs of people generating new information that was not available to either member of the pair. This surprising result was not attributable to artefacts linked to the complexity or familiarity of stimulus material, nor was it linked to variations in people's cognitive perspectives. No evidence of social facilitation of memories was therefore found: two people recalling together certainly pool their separate memories so as to outperform individuals but the social interaction does not appear to generate previously unavailable memories.     

Who remembers best? Individual differences in memory for events that occurred in a science museum

Individual differences in memory and suggestibility were assessed in an experiment involving 1989 people who attended the Exploratorium, a science museum located in San Francisco. Subjects watched a brief film clip of an assault and later answered questions about it. Approximately half received misinformation about some critical items. Four demographic variables (gender, educational level, age, and occupation) were examined to determine their impact on memory performance. The principle of discrepancy detection predicts that, compared to individuals with a good memory, people who have poor memory to begin with will be relatively suggestible (that is susceptible to misinformation). Some of our findings were consistent with this principle. For example, children (5–10 years) and elderly (over 65) were relatively inaccurate and also relatively suggestible. Other findings were not consistent with the principle, for example the finding that artists and architects were relatively accurate, but they were also highly suggestible.