Confidence depends on level of aggregation

The credible intervals that people set around their point estimates are typically too narrow (cf. Lichtenstein, Fischhoff, & Phillips, 1982). That is, a set of many such intervals does not contain the actual values of the criterion variables as often as it should given the probability assigned to this event for each estimate. The typical interpretation of such data is that people are overconfident about the accuracy of their judgments. This paper presents data from two studies showing the typical levels of overconfidence for individual estimates of unknown quantities. However, data from the same subjects on a different measure of confidence for the same items, their own global assessment for the set of multiple estimates as a whole, showed significantly lower levels of confidence and overconfidence than their average individual assessment for items in the set. It is argued that the event and global assessments of judgment quality are fundamentally different and are affected by unique psychological processes. Finally, we discuss the implications of a difference between confidence in single and multiple estimates for confidence research and theory.     

Interval and ratio reinforcement of a complex sequential operant in pigeons

Pigeons were required to produce exactly four pecks on each of two keys in any order for reinforcement. Correct response sequences were reinforced on either fixed-interval two-minute or fixed-ratio four schedules, with each correct sequence treated as a single response. Each pigeon developed a particular dominant sequence that accounted for more than 80% of all sequences. Sequence stereotypy was relatively unaffected by the temporal properties of the fixed-interval and fixed-ratio schedules. Response time (time from the first response in each sequence to the last) was also relatively unaffected by the temporal properties of the schedules. In contrast, response latency (time from end of one sequence to the beginning of the next) was markedly affected by the schedules. Latencies were long early in the interreinforcement interval and got shorter as the interreinforcement interval progressed. These data suggest that stereotyped response sequences become functional behavioral units, resistant to disruption or alteration by reinforcement variables that ordinarily influence the temporal spacing of individual responses.     

Gender displays in portrait photographs

Following the research of Goffman (1976) and Henley (1977) on sex differences in nonverbal behavior, 1,296 portrait photographs from high school and university yearbooks and from the media files of a university were analyzed for sex differences. Females smiled with a significantly greater frequency and expansiveness than males and head canted significantly more than males. Results supporting the hypothesis that males would face the camera more directly than females failed to reach the acceptable significance level. The prediction that persons working in opposite-sex roles would deintensify their gender displays failed to gain support.The author expresses appreciation to Bill Drell and Andrea Wilson for their assistance in data collection.     

The Impact of Time Proximity and Level of Generality on Attitude-Behavior Consistency1

This study examines the effects of (1) generality equivalence between attitudinal and behavioral entities and (2) the order and proximity of the attitude and behavior questions on the observed relationship between attitudes and behavior. The behaviors examined are sentence recommendations for six hypothetical defendants. The sample is composed of 185 line probation officers from New York State. The variables chosen conform to Martin Fishbein's model of behavioral intentions. As predicted, the observed relationship is affected by both level of specificity and proximity of the questions. Order of the questions has little effect.     

Verbal ability and mental processing speed

The notion that verbal ability is related to mental processing speed was examined using tasks that systematically varied in semantic content. Subjects' reaction times were measured in five tasks involving arrow matching, physical identity word matching, or taxonomic identity word matching. The findings indicated that matching tasks using different decision rules and different stimuli were all related to verbal ability. In fact, reaction time for subjects required to judge whether two arrows pointed in the same direction was the best predictor of verbal ability. One explanation of the results is that speed of information processing (a general factor) may be the important component of verbal ability which is measured by seemingly different matching tasks.     

Effects of degree of interpersonal similarity on physical distance and self-reported attraction: A comparison of uniqueness and reinforcement theory predictions

The apparently divergent similarity-attraction findings of the reinforcement theory and uniqueness theory researchers were investigated by exposing male (N = 45) and female (N = 45) subjects to conditions of slight, moderate, or high similarity relative to one comparison other. Similarity was manipulated by means of a bogus personality and attitude inventory. For the self-report measures, results consistent with reinforcement theory were obtained in that greater self-reported attraction to the partner was linearly related to increased similarity. Additionally, interpersonal distance was curvilinearly related to similarity. This distancing pattern reflected the fact that moderate similarity subjects positioned themselves relatively closer to the other person's chair than the slight or high similarity subjects. The physical distance results support the uniqueness theory notion that high similarity may have some aversive properties. The discrepancy between the physical distance and self-report results is discussed in terms of an implicit causal theory that subjects may have about interpersonal similarity (i.e., greater similarity is good).     

Chunking in recall of symbolic drawings

Three experiments explored memory for symbolic circuit drawings using skilled electronics technicians and novice subjects. In the first experiment a skilled technician reconstructed circuit diagrams from memory. Recall showed marked “chunking”, or grouping, by functional units similar to Chess Masters’ recall of chess positions. In the second experiment skilled technicians were able to recall more than were novice subjects following a brief exposure of the drawings. This advantage did not hold for randomly arranged symbols. In the third experiment the size of chunks retrieved systematically increased with additional study time. Supplementary analyses suggested that the chunking by skilled subjects was not an artifact of spatial proximity and chunk statistics, and that severe constraints are placed on any explanation of the data based on guessing. It is proposed that skilled subjects identify the conceptual category for an entire drawing, and retrieve elements using a generate-and-test process.     

Children's strategies in producing three-dimensional relationships on a two-dimensional surface

It is a common task to give children a picture containing implicit depth cues and to require them to extract depth information from it. The cues are always selected from the adult repertoire; little is known about children's production of their own cues. In this experiment, 5- to 10-year-old children were required to draw one object behind another in a situation in which adults invariably produce the further object partially occluded by the nearer. The results were an age-related decline in the tendency to segregate the objects and an increase in the tendency to group the objects using partial occlusion, with a cross-over at 8 years. At all ages some children drew one object inside the boundary of the other. It is argued that the results are composed of two tendencies, a gradual mastery of discrete scaling phenomena (e.g., “up” on the page means “further”) within a given style, and a set of decisions to be made between incompatible styles.