Social psychological models of choice behavior and drivers' left turns

ABSTRACT. The authors reanalyzed data from a simulated left-turn experiment (P. A. Hancock, J. K. Caird, S. Shekhar, & M. Vercruyssen, 1991) to test the adequacy of the nonlinear Gray-Tallman satisfaction balance model of choice behavior (L. N. Gray & I. Tallman, 1984) in predicting left turns. Participants (Hancock et al., 1991) were 40 experienced U.S. drivers who were exposed to simulated oncoming traffic; the size of the vehicle (motorcycle, compact vehicle, full-sized vehicle, delivery truck), its speed (10-70 mph, or 16-112 kmph), and the intervehicle time gap (3-9 s) varied. Hancock et al. (1991) measured (a) the likelihood of a left turn and (b) the occurrence of a collision. The probability of a left turn was greater for larger intervehicle time gaps and for oncoming smaller vehicles traveling at higher speeds. The Gray-Tallman (1984) model explained 69% of the variation in turning versus 57% for a linear regression model. In making decisions people tend to treat the values and costs affecting choices in a multiplicative, rather than linear, fashion. The Gray-Tallman model also has the potential for incorporating, both theoretically and mathematically, an unlimited range of potential values and costs that may influence left turn decisions.     

Voluntary euthanasia and the right to die: a dialogue with Derek Humphry

Both the terminally ill and those responsible for their care may experience conflict and limited freedom of choice with respect to the right to die. Derek Humphry, founder of the Hemlock Society, shares his personal experience, as well as his efforts to educate the public and stimulate legal reform. He has dedicated more than a decade of prime professional years to this highly charged universal problem.     

Lifeguards' vigilance: effects of child-adult ratio and lifeguard positioning on scanning by lifeguards

Observers recorded visual scanning by four lifeguards at three indoor public swimming pools. Scanning increased as a positive function of the ratio of children to adult swimmers, i.e., scanning was greater when the ratio was high, suggesting that lifeguards became more concerned about the risks to children and the ability of nearby adult swimmers to monitor these children when the number of children significantly exceeded the number of adults. Absolute numbers of children, however, decreased number of scans, possibly because of greater number of incidents and rule violations requiring lifeguards' attention which competed with watching the pool. Lifeguards were more likely to scan a pool area when they were in elevated towers versus standing on the pool decks. Lifeguards' scanning declined later in the day, possibly due to fatigue or because of competing activities of pool maintenance.     

Cardiovascular Responses to Television-Mediated Nonverbal Approach1

Two studies are reported which examined physiological responsiveness to changes in level of nonverbal intimacy cues expressed by a partner during an interview conducted across interactive television. Experiment 1 and Experiment 2 separately examined the effects of decreasing apparent interactive distance (produced by alteration of image size) and increasing eye-contact on subjects' heart rate and pulse amplitude. The findings suggest that shifts in these nonverbal approach cues are related to cardiovascular changes including bradycardia and a modest compensatory increase in pulse amplitude. The implications of these results are discussed in terms of the hypothesized relationship between cardiovascular functioning and information processing and practical considerations for the use of interactive television.