Determinants of infant visual fixation: evidence for a two-process theory

Three experiments were conducted to investigate the dynamics of the human infant's (4 months old) visual fixation. The general finding that, over a series of trials, infants fixate longer to a complex than to a simple stimulus was replicated. The function relating fixation time to trials was shown to be nonmonotonic when the stimulus was complex (fixation time increased between Trials 1 and 2 and then decreased), but was monotonic when the stimulus was simple (it decreased systematically over trials). Additional experiments indicated that (a) the nonmonotonic function associated with the complex stimulus was eliminated when the interval separating Trials 1 and 2 was increased from 10 to 20 or 30 s (Experiment 2), and (b) the difference in fixation time between the complex and the simple stimulus was eliminated by controlling their effects in a within-subjects design (Experiment 3). These data challenge the prevailing cognitive-schema theories as a complete account of the dynamics of the infant's visual fixation. A two-process theory that accounts for these data was proposed.     

The emergence of representation in search: Understanding the hider as an independent agent

Corrigan's results point the way toward a reconceptualization of how the development of representation affects search. The child does not cognitively recreate the invisible displacements of the object. Instead she seems to understand that the hider is an independent agent who can use simple hiding strategies that the child does not directly perceive. This representational skill for search, we propose, is one realization of a general representational capacity that emerges late in the second year. The general capacity is defined structurally as the ability to coordinate two sensorimotor systems into a single skill. Although there seem to be some discontinuities in the emergence of the representational capacity, its development is mostly gradual and continuous.     

Ambiguous-cue learning in preschool children: A test of the dimensional characteristics of task stimuli

Sixteen preschool children were administered a two-choice discrimination problem consisting of three stimulus compounds: the consistently rewarded stimulus, the consistently nonrewarded stimulus, and the ambiguous stimulus which was nonrewarded when paired with the positive, but rewarded when paired with the negative. When both pair of stimuli, positive-ambiguous and negative-ambiguous, were presented together the subject was required either to choose or to avoid the ambiguous stimulus depending upon the stimulus with which it was paired. In Experiment 1, when each of three stimuli (positive, negative, ambiguous) varied along one nonspatial cue dimension (color), performance was better on negative-ambiguous trials than positive-ambiguous trials. In Experiment 2, when the positive and negative stimuli varied along three nonspatial cue dimensions (colors and form) and the ambiguous stimulus varied along one of these dimensions (color), superior positive-ambiguous over negative-ambiguous performance was obtained. These findings complement those reported for other subjects and confirm Berch's (D. B. Berch, Learning and Motivation, 1974, 5, 135–148) predictions regarding use of differential numbers of cue dimensions.     

Perspective role-taking in young children

Children between the ages of 4 and 7 years were asked to select a photograph depicting the visual perspective of a puppet which was placed at various locations around a dollhouse in a modified version of Piaget and Inhelder's three-mountain task. A shielded condition was used for half of the children. Three types of errors were examined in relation to the shield condition, age, and type of vantage point (views from the corners and from the sides). Shielding of the stimulus array reduced egocentric errors among 4-year-olds, producing a pattern of responses more typical of that observed among older children. Increasing specificity in perspective role-taking with age was indicated by changes in error patterns. Finally, the task was more difficult on trials with corner views, particularly when the child's own view included some of the cues present in the puppet's perspective.     

Adaptation to work: An analysis of employee health, withdrawal, and change

J. Rosse and H. Miller (1984, in P. Goodman, R. Atkin et al., Absenteeism: New Approaches to understanding, measuring, and managing employee absence. San Francisco: Jossey-Bass) have proposed a model of employee adaptation that hypothesizes multiple withdrawal behaviors and attempts to change working conditions as alternative forms of adaptation to a dissatisfying work environment. Negative health outcomes are also hypothesized consequences of dissatisfaction with work. In this longitudinal study of 42 new hospital employees, intention to quit, turnover, absence, attempts to change the job, and heatlh disorders were negatively correlated with job satisfaction; lateness and self-report avoidance scale were not. Use of adaptive behaviors was also found to have remedial effects for employee health. Implications for a general model of adaptation are discussed.     

Bobo clown aggression in childhood: Environment,not genes

We videotaped 216 twin children (average age: 7.6 years) hitting a 5-ft “Bobo clown”. Three behaviors in the Bobo clown situation showed adequate response characteristics, rater reliability, and test-retest reliability: number of hits, intensity of hits, and number of quadrants (into which the Bobo clown was hit). In terms of two “anchor” variables, height and weight, the twin correlations were representative of other studies in suggesting substantial hereditary influence. However, twin analyses of the three behavioral ratings during the Bobo clown session yielded no evidence of hereditary influence. Moreover, the results provided evidence of substantial environmental influence of the “between-family” variety. In other words, the family environment is the major source of individual differences for these measures.