On mathematical illusions

A criticism of Walker’s (1973) paper on the grounds that its physiological premises lack support, that it misrepresents the theoretical position of Blakemore, Carpenter, and Georgeson (1970), and that its theory is contradicted by existing evidence.     

On the handling of heavy bias in a self-paced task

Following an earlier observation that systematic variations in performance on a task with heavy frequency imbalance was correlated with fluctuations in the amount of bias in the input programme, an experiment was carried out to establish the roles of long and short term sampling. Two groups of subjects were trained on a self-paced, five-choice task. One group's input had an average of 68 per cent. bias on one source, the other had 44 per cent. on the same source. Analysis of data was carried out on three levels of local bias for each condition, one level being identical for both conditions. It was found that responses to the biased stimuli were determined by the average bias in each input sequence and not by moment to moment variations in that bias. The effect observed originally can therefore be accounted for in terms of a relatively simple additive model which includes the “repetition effect” first described by Bertelson.     

Book reviews

Women as Teachers and Disciples in Traditional and New Religions. Elizabeth Puttick & Peter B. Clarke, eds., 1993 Lampeter: Edwin Mellen Press 146 pp., £48.24 ISBN 0–7734–9346–8

Vrouwen in de wereldgodsdiensten. Teksten, tradities en recente on‐twikkelingen [Women in the World Religions: Texts, Traditions and Recent Developments]. Catherine Cornille, 1994 Rotterdam: Lemniscaat 183 pp., Belgian francs 570.00 ISBN 90–6069–933–5

Shadow of Spirit: Postmodernism and Religion. Philippa Berry & Andrew Wernick, eds., 1992 London: Routledge 274 pp., £35.00 hb and £12.99 pb ISBN 0–415–06638–7 and 06639–5

Political Islam, a special volume of the Annals of the American Academy of Political and Social Sciences. Charles Butterworth & I. William Zartman, eds., 1992 London: Sage 232 pp., US$17.00 £14.95 ISBN 0–8039–4687–2

The Sociology of Sacred Texts. Jon Davies & Isabel Wollaston, 1993 Sheffield: Sheffield University Press 195 pp., £35.00 ISBN 1–85075–404–7

A Generation of Seekers: The Spiritual Journeys of the Baby Boom Generation. Wade Clark Roof, 1993 New York: Harper Collins Publishers, Harper, San Francisco US$12.00 Aus$24.95 ISBN 006–066–9640

The American Encounter with Buddhism 1844–1912. Victorian Culture and the Limits of Dissent. Thomas A. Tweed, 1992 Bloomington, Indianapolis: Indiana University Press xxiv + 242 pp., US$29.95(h/b) ISBN 025–336–0994

Visions of Reality: What Fundamentalist Schools Teach. Albert J. Menendez, 1993 Buffalo, New York: Prometheus Books 152 pp., £12.50 ISBN 0–87975–802–3     

Collaborative Consultant: A New Role for Counselors Serving At-Risk Youths

School and community counselors have important roles in developing and implementing mental health programs for youths and families. Counselors who are working with the more complex issues of at-risk youths can enhance implementation of prevention programs by altering their roles to function within a collaborative consultation model. This model represents a new paradigm in that counselors interdependently and collaboratively partner with people previously considered their “consultees.” Such collaboration can result in more comprehensive and integrated programs, and it can prevent fragmentation and duplication of efforts. Collaborative consultation is described and contrasted with more traditional consultation models, and a 5-stage implementation process is presented. Personal and systemic factors that support the collaborative process are examined.     

Young infants'' sensitivity to movement information specifying social causality

Adults and 3- to 6-month-old infants were tested for their visual preference for two different dynamic displays presented simultaneously on two side-by-side computer monitors. Each display consisted of a pair of colored discs moving either independently (the independent display) or in systematic interaction (the “chase” display), never actually contacting one another. Except for the relative spatio-temporal dependence of the discs' movements, all dynamic parameters on the two displays were controlled and maintained equal. Analysis of looking behavior showed that adults as well as infants looked differentially at the displays. Patterns of preference depended on age. For the infants who completed the experiment, there was a significant transition from more looking at the chase to more looking at the independent display as a function of age. Adults as well as the older, attentive infants, showed enhanced visual attention to the independent display. These results provide first evidence of young infants' sensitivity to movement information specifying social causality for adult observers.     

Reasons for,and consequences of,revealing personal secrets in close relationships: A longitudinal study

This investigation examines whether individuals’ reasons for keeping secrets predict whether they eventually reveal those secrets and whether individuals can accurately anticipate the outcomes of revealing. Respondents (n= 342) first reported on a secret they were keeping and then returned 2 months later to report whether they had revealed it and, if so, what happened when they did. Findings indicated that participants’ reasons for keeping a secret predicted whether they revealed it. The results also indicated both accuracy and inaccuracy in secret tellers’ expectations of the outcomes of revealing a secret. Finally, despite some demonstrable inaccuracies in the forecasted outcomes, participants’ retrospective accounts after revealing suggested that participants typically believed that they had accurately predicted the consequences of revealing.     

Twelve-month-olds communicate helpfully and appropriately for knowledgeable and ignorant partners

In the current study we investigated whether 12-month-old infants gesture appropriately for knowledgeable versus ignorant partners, in order to provide them with needed information. In two experiments we found that in response to a searching adult, 12-month-olds pointed more often to an object whose location the adult did not know and thus needed information to find (she had not seen it fall down just previously) than to an object whose location she knew and thus did not need information to find (she had watched it fall down just previously). These results demonstrate that, in contrast to classic views of infant communication, infants' early pointing at 12 months is already premised on an understanding of others' knowledge and ignorance, along with a prosocial motive to help others by providing needed information.     

Highlighting human form and motion information enhances the conspicuity of pedestrians at night

Exploring how biological motion can make pedestrians more conspicuous to drivers at night, one-hundred-and-twenty participants were driven along an open-road route at night and pressed a button whenever they recognized that a pedestrian was present. A test pedestrian wearing black clothing alone or with 302 cm2 of retroreflective markings in one of four configurations either stood still or walked in place on an unilluminated sidewalk. Participants' response distances were maximal for the full biological-motion configuration and remained surprisingly long when convenient subsets of reflective markers were positioned on the pedestrian's ankles and wrists. When the pedestrian wore a reflective vest, the responses were no better than when he wore no reflective markings. The biological-motion advantage actually results from interacting form-perception and motion-perception mechanisms. These results confirm that basic perceptual phenomena-observers' sensitivity to human form and motion can be harnessed to reduce an important problem of traffic safety.