No abstract

Two experiments studied how 5- to 10-year-olds integrate perceptual causality with their knowledge of the underlying causal mechanism. Children learned about 2 devices by which a ball dropped into one end of a box made a bell ring at the other end, either immediately (contiguous mechanism) or after a delay (noncontiguous mechanism). When 1 ball was dropped first and a 2nd ball was dropped after a delay, and then the bell rang immediately, 5- and 7-year-olds chose the contiguous cause regardless of the mechanism inside. This was not due to lack of specific knowledge or problems with salient distractors. The results suggest a link between temporal contiguity and causality in children's understanding. Children also considered causal mechanism, in agreement with previous research, but they may not understand that mechanism is superordinate to perceptual cues for causality.

Two experiments used Information Integration Theory to study how children judge expected value of complex gambles in which alternative outcomes have different prizes. Six-year-olds, 9-year-olds and adults (N = 73 in Study 1, N = 28 in Study 2) saw chance games that involved shaking a marble in a bicolored tube. One prize was won if the marble stopped on blue, another if it stopped on yellow. Children judged how happy a puppet playing the game would be, with the prizes and probability of the blue and yellow outcomes varied factorially. Three main results appeared in both studies: First, participants in all age groups used the normatively prescribed multiplication rule for integrating probability and value of each individual outcome--a striking finding because multiplicative reasoning does not usually appear before 8 years of age in other domains. Second, all age groups based judgment of overall expected value meaningfully on both alternative outcomes, but there were individual differences--many participants deviated from the normative addition rule, showing risk seeking and risk averse patterns of judgment similar to the risk attitudes often found with adults. Third, even the youngest children took probability to be an abstract rather than physical property of the game. Overall, in contrast to the traditional view, the present results demonstrate functional understanding of probability and expected value in children as young as 5 or 6. These results contribute to the growing evidence on children's intuitive reasoning competence. This intuition can, on the one hand, support surprisingly precocious performance in young children, but it may also contribute to the biases evident in adults' judgment and decision.

Two experiments investigated Michotte's launch event, in which successive motion of two objects appears to evoke an immediate perception that the first motion caused the second, as in a collision. Launching was embedded in event sequences where a third event (a colour change of the second object) was established as a competing predictor of the second motion, in an attempt to see whether subjects' learning of alternative predictive relationships would influence their causal impressions of launch events. In Experiment 1 subjects saw launch events in which temporal contiguity at the point of impact was varied so that an impact itself did not reliably predict when the second object would move. Half of these scenes, however, contained a colour change of the second object which did reliably predict when it would move. In accordance with Michotte's theory, subjects' ratings of the degree of perceived causality were not affected by the colour change. In Experiment 2 subjects saw scenes that contained launch events with or without temporal contiguity and a colour change. These were interspersed with events in which a colour change alone did or did not precede the second motion. Thus, movement of the second object was either contingent on or independent of the impact. Subjects repeatedly (a) rated perceived causality in single launch events and (b) judged the necessity of collisions for movement in the overall set of events. These responses dissociated, in that ratings of type (a) showed only a substantial contiguity effect, whereas judgements of type (b) showed both a contingency and a much smaller contiguity effect. These results appear to support a distinction between judged and perceived causality and are discussed with respect to Michotte's theory of direct causal perception.

Phenomenal causality was studied by using Michotte's launch event, in which successive motion of two objects evokes an immediate perception that the first motion causes the second. Information integration theory was used to address the complementary issues of invariant perceptual structure and individual differences in phenomenal causality. Three informational cues were varied conjointly: temporal and spatial contiguity of the two motions, and the ratio of their speeds. The dependent measure was a judgment of degree of causality or naturalness. The results showed that individual differences were related to these instruction conditions; the subjects showed five distinctive response patterns. Two were the modal patterns elicited by the instructions, and the others fell in between. The averaging model gave a good account of the data, with meaningful parameter estimates. Individual differences were localized in cue evaluation, whereas their integration into a unified judgment followed an invariant averaging rule. The results allow some reconciliation between Michotte and his critics.