Decision theoretic foundations for axioms of rational preference

Rationality postulates for preferences are developed from two basic decision theoretic principles, namely: (1) the logic of preference is determined by paradigmatic cases in which preferences are choice-guiding, and (2) excessive comparison costs should be avoided. It is shown how the logical requirements on preferences depend on the structure of comparison costs. The preference postulates necessary for choice guidance in a single decision problem are much weaker than completeness and transitivity. Stronger postulates, such as completeness and transitivity, can be derived under the further assumption that the original preference relation should also be capable of guiding choice after any restriction of the original set of alternatives.     

The Effects of Mandatory Time Limits in the Voting Booth on Liberal-conservative Voting Patterns

One hundred and forty college students, in either (a) 2-minute time-limit or (b) a no-time-limit condition, voted their conscience on actual pending legislation in their state in a test of hypothesis that such time limits in the voting booth created a stimulus overload situation. Such a situation was expected to result in dysfunctional adaptation responses, with unintended effects on voting patterns. Results indicated that subjects in the time stress condition voted significantly more conservatively on these issues. This conservative shift is interpreted as a function of overload, with serious political implications for urban planners, whose response to increasing population density often has been to increase the tempo by which citizens are processed through the cities'institutional and social services.     

Sex differences in conformity: Instrumental or communal response?

Male and female introductory psychology students (N=88) were asked to read a clinical case history and the opinion consensus of either (a) their peers, (b) advanced psychology students, or (c) Ph.D. clinical psychologists that the patient should be hospitalized for at least 90 days (an extreme treatment). Subjects then indicated on a scale of 10 to 90 days, the length of hospitalization they thought best. In a significant interaction effect (sex of subject × expertise of source) males were least influenced by the opinions of their peers and increasingly influenced as the source became more expert. Females, however, seemed most influenced by their peer group, recommending longest hospitalization terms in that condition. Results are interpreted in terms of sex-role identification and the emergence of an instrumental (task) or communal set.     

Do we Need a Special Ethics for Research?

Research is subject to more stringent ethical requirements than most other human activities, and a procedure that is otherwise allowed may be forbidden in research. Hence, risk-taking is more restricted in scientific research than in most non-research contexts, and privacy is better protected in scientific questionnaires than in marketing surveys. Potential arguments for this difference are scrutinized. The case in its favour appears to be weak. A stronger case can be made in favour of a difference in the opposite direction: If perilous or otherwise problematic activities have to be performed it is usually better to perform them in a research context where they are properly evaluated so that guidance is obtained for the future. However, retreating from current ethical demands on research is not a desirable direction to go. Instead, research ethics can serve to inspire the introduction of more stringent ethical principles in other social sectors.     

Genetic and environmental influences on mothering of adolescents: a comparison of two samples

This study examined 2 samples of adolescents and mothers using a child-based design (Nonshared Environment in Adolescent Development [NEAD] project, N = 395 families) and a parent-based design (Twin Moms [TM] project, N = 236 twin family pairs) to compare genetic and environmental influences on mothering. For both samples, the same measures of positivity, negativity, control, and monitoring were used. The use of matched child-based and parent-based samples enabled passive and nonpassive genotype-environment (GE) correlations to be approximated, providing information about process. Passive GE correlations were suggested for mother's positivity and monitoring. For mother's negativity and control, primarily nonpassive GE correlations were suggested. In several cases, both types of GE correlation were indicated. Finally, observer ratings of negativity and monitoring were influenced only by environmental factors.     

Order-Independent Transformative Decision Rules

A transformative decision rule alters the representation of a decision problem, either by changing the set of alternative acts or the set of states of the world taken into consideration, or by modifying the probability or value assignments. A set of transformative decision rules is order-independent in case the order in which the rules are applied is irrelevant. The main result of this paper is an axiomatic characterization of order-independent transformative decision rules, based on a single axiom. It is shown that the proposed axiomatization resolves a problem observed by Teddy Seidenfeld in a previous axiomatization by Peterson.     

Selective Revision

We introduce a constructive model of selective belief revision in which it is possible to accept only a part of the input information. A selective revision operator ο is defined by the equality K ο α = K * f(α), where * is an AGM revision operator and f a function, typically with the property ⊢ α → f(α). Axiomatic characterizations are provided for three variants of selective revision. This revised version was published online in June 2006 with corrections to the Cover Date.     

Providing Foundations for Coherentism

We prove that four theses commonly associated with coherentism are incompatible with the representation of a belief state as a logically closed set of sentences. The result is applied to the conventional coherence interpretation of the AGM theory of belief revision, which appears not to be tenable. Our argument also counts against the coherentistic acceptability of a certain form of propositional holism. We argue that the problems arise as an effect of ignoring the distinction between derived and non-derived beliefs, and we suggest that the kind of coherence relevant to epistemic justification is the coherence of non-derived beliefs. This revised version was published online in July 2006 with corrections to the Cover Date.     

Neuroleptic-induced attenuation of brain stimulation reward in rats.

In 30-min free-operant tests, the dopamine receptor blockers pimozide (.125, .25, and .50 mg/kg) and (+)-butaclamol (.1, .2, and .4 mg/kg) attenuated lever pressing for lateral hypothalamic brain stimulation. When discrete self-stimulation trials were offered in a straight alleyway, pimozide increased start box latencies, slowed running speeds, and reduced lever-pressing rates. However, performance early in both lever-pressing and runway sessions was normal; performance deteriorated as testing progressed, following patterns that paralleled those seen when animals were tested with reductions in the amplitude of stimulating current. Spontaneous recovery was obtained in both situations; experimenter-imposed 10-min time-outs caused renewed lever pressing and running. In contrast, alpha-noradrenergic receptor blockade by phenoxybenzamine (5, 10, and 20 mg/kg) failed to produce extinction-like response patterns. These data support the view that central dopaminergic systems are important components of the neural mechanisms mediating reward.     

Altruism Toward a Deviant in City and Small Town

A field experiment using the "Lost Letter Technique" tested the hypothesis that altruism would be higher in small towns than in cities, unless the person needing help was a social deviant. The hypothesis was derived from Milgram's (1970) overload theory, in which city dwellers are expected to become generally indifferent to, and make fewer differentiations between, unimportant others. A total of 216 letters to one of three addressees (control, somewhat deviant, highly deviant) were "lost", one-half in Tulsa, Oklahoma (population: 347,600) and one-half among 51 small, Oklahoma towns (× population: 2,002). Return rates supported the hypothesis. The data also suggest that a greater intolerance in small towns for social deviance might systematically overwhelm their generally higher levels of social responsibility. Implications are drawn regarding the danger of overgeneralizing negative attributions to urban centers.