Causal Probability

Examples growing out of the Newcomb problem have convinced many people that decision theory should proceed in terms of some kind of causal probability. I endorse this view and define and investigate a variety of causal probability. My definition is related to Skyrms' definition, but proceeds in terms of objective probabilities rather than subjective probabilities and avoids taking causal dependence as a primitive concept.     

Changing your mind

When individuals detect an inconsistency in a set of propositions, they tend to change their minds about at least one proposition to resolve the inconsistency. The orthodox view from William James (1907) onward has been that a rational change should be minimal. We propose an alternative hypothesis according to which individuals seek to resolve inconsistencies by explaining their origins. We report four experiments corroborating the explanatory hypothesis. Experiment 1 showed that participants’ explanations revised general conditional claims rather than specific categorical propositions. Experiment 2 showed that, when explanations did revise the categorical proposition, participants also tended to deny the consequences of a second generalization. Experiment 3 showed that this tendency persists when participants previously affirmed these consequences explicitly. Experiment 4 showed that, when participants could easily explain an inconsistency by revising a generalization, they were more likely to accept the consequences of a second generalization. All four results contravene minimalism but support the explanatory hypothesis.     

The Effects of Truth–Lie Base Rate on Interactive Deception Detection Accuracy

Consistent with the Park and Levine's (PL) probability model of deception detection accuracy, previous research has shown that as the proportion of honest messages increases, there is a corresponding linear increase in correct truth–lie discrimination. Three experiments (N = 120, 205, and 243, respectively) varied the truth–lie base rate in an interactive deception detection task. Linear base‐rate effects were observed in all 3 experiments (average effect r#x02009;= .61) regardless of whether the judges were interactive participants or passive observers, previously acquainted or strangers, or previously exposed to truths or lies. The predictive power of the PL probability model appears robust and extends to interactive deception despite PL's logical incompatibility with interpersonal deception theory.     

Lateral preferences and writing hand posture in left-handers: A reply to Levy

In reply to the commentary from J. Levy about a recent article of ours (A. Searleman, C. Porac, & S. Coren, 1984, Brain and Cognition, 3, 86–93), we find that she has shifted the level of analysis from between-sex comparisons (as demanded by our original hypothesis) to within-sex comparisons. Since she is addressing a different set of questions, we therefore find no compelling reasons to alter any of our conclusions or the confidence that we have in these conclusions.     

The theory of nomic probability

This article sketches a theory of objective probability focusing on nomic probability, which is supposed to be the kind of probability figuring in statistical laws of nature. The theory is based upon a strengthened probability calculus and some epistemological principles that formulate a precise version of the statistical syllogism. It is shown that from this rather minimal basis it is possible to derive theorems comprising (1) a theory of direct inference, and (2) a theory of induction. The theory of induction is not of the familiar Bayesian variety, but consists of a precise version of the traditional Nicod Principle and its statistical analogues.     

Choice vs. Preference: The Effects of Choice and No Choice of Preferred and Non Preferred Spelling Tasks on the Academic Behavior of Students with Disabilities

The effects of choice and no choice of preferred and non preferred instructional activities on the academic behavior of 3 students with disabilities were investigated. Participant preferences for spelling tasks were assessed and an ABCDEF design was used to examine choice and preference within 6 experimental conditions: a) choice of preferred tasks, b) choice of non preferred tasks, c) no choice of preferred tasks, d) no choice of non preferred tasks, e) no choice of preferred tasks (yoked-control), and f) no choice of non preferred tasks (yoked-control). Results indicate that all 3 participants had higher levels of task engagement when working with preferred tasks, regardless of a choice or no choice format. The findings from this investigation contribute to the growing body of research that focuses on developing interventions that are responsive to individual student preferences.     

The excuses of child molesters

Clinicians often regard the excuses of child molesters as important indicators of remorse, rehabilitation potential and the likelihood of recidivism. Despite the implications for clinical decision-making and judicial deliberations, relatively little is known about the content and structure of these explanatory statements. This study was an attempt to delineate the range of thematic content and logical structure of the excuses of child molesters. Over 250 justificatory statements were examined from the clinical records of 86 child molesters referred for psychiatric assessment. A total of 21 distinct excuses and six thematic categories were identified. An ‘excuse syntax’ was devised to define the structure of the offenders' reasoning about their sexual improprieties. The excuse syntax has the advantage of formalizing clinical judgements about the individual's level of denial and personal responsibility, his degree of defensiveness and the logical consistency of his justifications. Implications for clinical practice and research are discussed.     

The assessment of components involved in illusion formation using a long-term decrement procedure

Available evidence seems to indicate that illusion decrement represents reorganization of cognitive components involved in visual-geometric illusions. Observers viewed one of the two forms of the Mueller-Lyer illusion, containing differential opportunities for peripheral structural interactions, for a 10-min test session on each of 5 successive days. The magnitude of the distortion decreased to a different asymptotic level in each of the two configurations with the form, with more opportunity for structural interactions showing the higher asymptote. Thus, this asymptote probably represents the structural or physiological contribution to the illusory distortion.     

The fading of stabilized images: Eye movements and information processing

Two experiments are reported which indicate that neural and photochemical satiation processes are inadequate to explain the fading of the stabilized retinal image. When eye movements are attempted over the stimulus, fading occurs more rapidly, indicating an information processing component in the disappearance of the image.