Engaging Narratives and the Limits of Lay Ethics: Introduction

How can one discover the ethical issues associated with nanotechnologies? One heuristic is to tend closely to the ethical reflections of lay publics and the ways in which these are informed by experience with technological innovation, technology governance, and the (broken) promises of visionary science and technology. A close collaboration between social scientists and philosophers took this heuristic to its limits: On the one hand, it achieved remarkably fine–grained insights into public reflection about nanotechnologies. On the other hand, a philosophical analysis of these reflections makes apparent that there is a profound disconnect between the lay ethics rooted in public talk and the ethical and normative commitments that are embedded in nanotechnological research programs and practices. Accordingly, critical engagement with the ways in which ordinary people try to make sense of nanotechnologies constitutes a novel heuristic for the discovery of ethical issues. This introduction and the subsequent four papers show this heuristic at work.     

Stimulus-response compatibilities during top-bottom discriminations.

Participants indicated whether a small dot was located near the top or bottom pole of a rotated object. Response times increased as a function of object orientation more for top trials than for bottom trials. The interaction between orientation and response was shown to be due to a relationship between response times and the dot's height on the screen. The orientation effect was influenced, positively and negatively, by a vertical arrangement of the response keys depending on whether the upper or lower key was used for the top response. Horizontal key placement produced an intermediate orientation effect, with asymmetries of about 180 degrees depending on which hand was used for top responses. This task appears to reflect spatial stimulus-response compatibilities more than object processing.     

Process causality and asymmetry

Process theories of causality seek to explicate causality as a property of individual causal processes. This paper examines the capacity of such theories to account for the asymmetry of causation. Three types of theories of asymmetry are discussed; the subjective, the temporal, and the physical, the third of these being the preferred approach. Asymmetric features of the world, namely the entropic and Kaon arrows, are considered as possible sources of causal asymmetry and a physical theory of asymmetry is subsequently developed with special reference to the questions of objectivity and backwards causation.An earlier draft of this paper was read at the A.A.P. conference at the University of Sydney, June, 1990. The author would like to thank Peter Menzies and Huw Price for their helpful comments.     

The schedule dependency of the signaled reinforcement effect

In Experiment 1, rats leverpressed for food reinforcement on either a variable ratio (VR) 30 schedule or a variable interval (VI) 15-s schedule. One group in each condition received a signal filling a 500-ms delay of reinforcement. This treatment enhanced rates on the VR schedule, and attenuated rates on the VI schedule, relative to the rate seen in an unsignaled control condition. In Experiment 2 there was no delay of reinforcement and the signal and food were presented simultaneously. Attenuated rates of responding were observed on VI schedules with a range of mean interval values (15 to 300 s). Experiment 3 used a range of VR schedules (10 to 150) with simultaneous presentations of signal and food. A signal-induced enhancement of response rate was found at all VR values. In Experiment 4, a signal elevated response rates on a tandem VI VR schedule, but depressed rates on a tandem VR VI schedule, compared to control conditions receiving unsignaled delayed reinforcement. These results are taken to show that the effect of a signal accompanying reinforcement depends upon the nature of the behavior that is reinforced during exposure to a given schedule.     

Visual Reinforcement Signals Interfere with the Effects of Reinforcer Magnitude Manipulations

Three experiments examined the effect of reinforcement magnitude on free-operant response rates. In Experiment 1, rats that received four food pellets responded faster than rats that received one pellet on a variable ratio 30 schedule. However, when the food hopper was illuminated during reinforcer delivery, there was no difference between the rates of response produced by the two magnitudes of reward. In Experiment 2, there was no difference in response rates emitted by rats receiving either one or four pellets of food as reward on a random interval (RI) 60-s schedule. In Experiment 3, rats responding on an RI 30-s schedule did so at a lower rate with four pellets as reinforcement than with one pellet. This effect was abolished by the illumination of the food hopper during reinforcement delivery. These results indicate that the influence of magnitude is obscured by manipulations which signal the delivery of reinforcement.     

The importance of conduct problems and depressive symptoms in predicting adolescent substance use

The current study assessed the relative importance of conduct problems and depressive symptoms, measured at two ages (11 and 15), for predicting substance use at age 15 in an unselected birth cohort of New Zealand adolescents. Among males, when the relative predictive utility of both conduct problems and depressive symptoms was assessed, only pre-adolescent depressive symptoms were found to predict multiple drug use 4 years later. No predictive relation was found between early symptomatology and later substance use among females. The strongest association between predictors and substance use emerged between age 15 multiple drug use and concurrent conduct problems for both males and females. Finally, both conduct problems and depressive symptoms at age 15 were also found to be associated with concurrent self-medication among females.This work was supported by USPHS grants MH-43746 and MH-45070 from the Antisocial and Violent Behavior Branch of the National Institute of Mental Health to Terrie Moffitt. Bill Henry was funded by a Fulbright Travel Award. The Dunedin Multidisciplinary Health and Development Research Unit is supported by the Medical Research Council and Health Research Council of New Zealand. Appreciation is expressed to the interviewers who collected the data, and to the young New Zealanders who were members of the sample.