Explanation and the theory of questions

In The Scientific Image B. C. van Fraassen argues that a theory of explanation ought to take the form of a theory of why-questions, and a theory of this form is what he provides. Van Fraassen's account of explanation is good, as far as it goes. In particular, van Fraassen's theory of why-questions adds considerable illumination to the problem of alternative explanations in psychodynamics. But van Fraassen's theory is incomplete because it ignores those classes of explanations that are answers not to why-questions but to how-questions. In this article I provide a unified theory of explanatory questions that comprehends both how-questions and why-questions, and I show that a question-theoretic approach to explanation can be defended independently of van Fraassen's programme of Constructive Empiricism.     

Effects of anxiety sensitivity on emotional response to a stress task

The purpose of this investigation was to further define the role of anxiety sensitivity, in relation to physiological arousal and the cognitive perception of anxiousness, as a determinant of anxiety. One hundred and thirty-two undergraduates at an urban university served as subjects. Two physiological measures of arousal and two cognitive measures of anxiety were used following an anxiety inducing task (mental arithmetic). The general expectation, which was supported, was that individual differences in anxiety sensitivity levels are more closely related to subjects' reported anxiousness in stressful conditions than are the actual physiological changes. Additionally, anxiety sensitivity was related to poststress levels of anxiety whereas trait anxiety was only related to pre- and postrelaxation levels of anxiety. Implications of the findings are addressed.     

Intuitive Perceptions of Decision-making Strategy: Naive Assessors' Concepts of Integrative Complexity

Although there are measurable differences in integrative complexity among solutions that individuals generate in dealing with problems, it is uncertain to what extent people comprehend, recognize, and have preferences among different levels of complexity. Integrative complexity is a function of differentiation (the perception of several attributes within, or perspectives about, a topic) and integration (combining the differentiated characteristics in an interactive or synthesizing solution). The current paper reports two experiments dealing with how university students perceive, interpret, and choose among solutions differing in complexity. Experiment 1 showed that subjects accurately rated the complexity of described solutions differing along the continuum, but that their assessment of their own responses differed from the results of expert scoring. Their self-estimated complexity was highly correlated with their preferences, and preferred complexity was reliably higher than either expert- or self-assessed complexity of subject-generated solutions. Subjects were able to hypothesize quite accurately about environmental and endogenous factors likely to affect complexity. Experiment 2 found that in response to problem scenarios, solutions selected as being potentially most effective were consistently more complex than solutions that participants considered themselves most likely to use. The idea of complexity seems to be intuitively recognizable and understandable by untrained subjects: They can and do distinguish among problem solutions (self-generated or presented) that vary on that dimension, and are able to assess accurately the effects of relevant variables. Such subjects also share the bias shown by experts in favour of the superiority of more complex approaches.     

Social Perceptions of Termination of Medical Treatment: Suicide or Rational Decision?

In two studies, college students read about a critically ill patient who died after CPR attempts failed, CPR was not attempted pursuant to a "Do-Not-Resuscitate" (DNR) order, he terminated all medical treatment, or he self-administered a lethal injection. Death resulting from treatment termination was perceived as significantly more unconventional than were death by CPR failure or DNR order. Ending treatment and lethal injection were perceived as equivalent acts of suicide, and resulted in the patient's being seen as less rational and less capable of making health care decisions. Timing of the patient's decisions regarding treatment, as indicated by the presence or absence of Living Will information, did not alter these perceptions. Results are discussed in light of opposing hypotheses regarding views of "naive" social perceivers toward actions with identical outcomes: that acts of commission are perceived as causal and rated more negatively than acts of omission (Spranca, Minsk, & Baron, 1991), and that acts seen as abnormal are attributed greater causal impact (Hilton & Slugoski, 1986).     

Moderation and Mediation of HIV-Prevention Interventions: Relationship Status,Intentions, and Condom Use Among College Students1

This study examined the effects of 2 HIV prevention interventions on condom use and mediators of condom use. College students were randomly assigned to a control condition or an intervention (communication skills or technical skills). Those who received either intervention had greater condom use self-efficacy, more positive condom use attitudes, and stronger intentions to use condoms than did controls. Furthermore, 3-month follow-up data revealed that students in either intervention who were not in a steady dating relationship reported more consistent condom use than did those in the control condition, whereas students who were in either intervention and in a relationship reported somewhat less consistent condom use than did those in the control condition. Analyses suggested that effects of the interventions on condom use were mediated by increased intentions to use condoms.     

Bad Rap for Rap: Bias in Reactions to Music Lyrics1

This research examines the recent public outcry against violent rap songs such as Ice T's “Cop Killer.” It was hypothesized that rap lyrics receive more negative criticism than other types of lyrics, perhaps because of their association with Black culture. Two experiments were conducted to examine the effect of musical genre and race of singer on reactions to violent song lyrics. The results support the hypothesis. When a violent lyrical passage is represented as a rap song, or associated with a Black singer, subjects find the lyrics objectionable, worry about the consequences of such lyrics, and support some form of government regulation. If the same lyrical passage is presented as country or folk music, or is associated with a White artist, reactions to the lyrics are significantly less critical on all dimensions. The findings are briefly discussed in terms of various models of racism and stereotyping.     

Influence of Destabilization on the Temporal Characteristics of lquot;Volitionalrquot; Stepping

Previous work suggests that there may be fundamental differences between compensatory stepping responses evoked by postural perturbation and visually cued "volitional" stepping (e.g., gait initiation). In contrast to visual cueing, postural destabilization evokes an array of sensory inputs that are intrinsically linked to the mobilization of rapid compensatory responses. The hypothesis examined in this study was that this fundamental difference would lead to distinct changes in the temporal characteristics of the stepping response. Six healthy young adults were instructed to step quickly in response to either visual cueing or anterioposterior platform motion. Both forward and backward stepping responses were characterized, using measures of vertical ground reaction force. A stereotypical temporal patterning of the stepping response occurred in both stimulus conditions and both directions of stepping, and anticipatory postural adjustments were evident in all trials. However, postural destabilization led to a more rapid initiation and execution of the temporal pattern, in comparison with visually cued responses. The most pronounced effect was seen in the duration of the response, which was reduced by a factor of two, with approximately proportional foreshortening of both the preparatory and swing phases. The results suggest that sensory information conveying a state of instability has a distinct influence on the characteristics of a subsequent stepping reaction. The persistence of the anticipatory postural adjustments suggests that the failure to see this element of the response in previous studies may reflect fundamental differences between volitional and unplanned compensatory stepping.     

Human Signal-detection Performance: Effects Of Signal Presentation Probabilities And Reinforcer Distributions

University students participated in one of four standard two-choice signal-detection experiments in which signal presentation probability was varied and the reinforcement distribution was held constant and equal. In Experiments 1, 3 and 4, subjects' performance showed a systematic response bias for reporting the stimulus presented least often. Experiments 1 and 4 showed that this effect was reliable with extended training and monetary, rather than point, reinforcement. In Experiment 2, all correct responses were signaled in some way, and this produced the opposite relationship between signal presentation probability and response bias. Experiments 1 and 3 found that explicitly deducting money (intended as punishment) for equal numbers of incorrect responses on each alternative, or varying the obtained overall rate of reinforcement, produced no clear change in response bias. The bias, shown by humans, for reporting the stimulus presented least often remains a challenge for theories of stimulus detection.