Indicative conditionals,conditional probabilities,and the “defective truth-table”: A request for more experiments

While there is now considerable experimental evidence that, on the one hand, participants assign to the indicative conditional as probability the conditional probability of consequent given antecedent and, on the other, they assign to the indicative conditional the “defective truth-table” in which a conditional with false antecedent is deemed neither true nor false, these findings do not in themselves establish which multi-premise inferences involving conditionals participants endorse. A natural extension of the truth-table semantics pronounces as valid numerous inference patterns that do seem to be part of ordinary usage. However, coupled with something the probability account gives us—namely that when conditional-free ? entails conditional-free ψ, “if ? then ψ” is a trivial, uninformative truth—we have enough logic to derive the paradoxes of material implication. It thus becomes a matter of some urgency to determine which inference patterns involving indicative conditionals participants do endorse. Only thus will we be able to arrive at a realistic, systematic semantics for the indicative conditional.     

Variable Credibility Threats: A Procedure for the Enhancement of Deterrence Effectiveness1

This experiment evaluated a procedure whereby tax evasions can be more effectively deterred by dividing the taxpayers' population into two, high- and low-audit probability, categories. The procedure employs a rule that assigns tax evaders to the high-audit probability category and assigns those who abide by the law to a low-audit probability category. A simple empirical simulation showed that the “variable probabilities” procedure prevented tax evasions more effectively than an alternative, “fixed probability” procedure, in which the same audit probability applied to all individuals, regardless of their past record.     

条件推理:“演绎”与“概率”两种实验研究范式之比较

本研究通过推理心理学研究中的“演绎”和“概率”两种实验范式设计对同一个班级的大学生参与者(实验一中N=57,实验二中N=43)进行先后两次有关条件推理的实验研究后,得出如下主要结果:(1)推理者在对不同的“纯形式条件命题本身的认可度”以及对由它们各自建构的同类型推理题的推理结果之间的作答反应模式之间的差异都很小且具有较高的一致性;(2)对由不同的“含具体内容的假言命题”本身的认可度之间以及由它们建构的同类型条件推理题的推理结果之间具有较大的差异性;(3)推理者对“演绎”和“概率”两种不同实验范式分别建构的内容近似的推进题进行推理时具有大致相同的作答反应趋势。由此可以推论推理者在“概率推理实验范式”中的作答或推理结果可以被视为只是对“演绎推理实验范式”的相应推理题给出“概率解”的心理加工过程。     

The problem of switching in conditional behavior

This article reviews studies of various authors on the phenomenon of “switching,” which is observed in both classical and instrumental conditioning and consists in elicitation of different responses to the same conditional stimulus (CS) when it is applied in an environment different than the original one. The different responses include a decrease or an absence of the previously trained conditional response (CR), elicitation of an appetitive response instead a defensive one, or vice versa, as well as elicitation of two different instrumental CRs in the same trial. The studies suggest that, due to the repeated occurrence of CS in the same environment (E), also called “situation” or “context,” associations are formed between CS and E. Consequently, the CR is elicited to a compound CS+E rather than to CS alone. When the CS is applied alone in a different E than the original one, the previously formed associations are inactive and the CR cannot be elicited; this leads to switching. Studies also suggest that E plays a dominant role in conditioning compared with that of CS alone, which often appears to be only a trigger for eliciting the response. However, CS tested in a different E may still produce some components of the previously acquired CR, such as a general fear behavior to an originally defensive CS or an approach behavior to an originally alimentary CS. The environmental stimuli can be considered the “determining” stimuli that determine the kind of reaction to be elicited, or “tonic” stimuli that increase the tonus in the brain but do not elicit the CR. The “determining” or “tonic” stimuli do not seem to be a special class of stimuli. Instead, they are stimuli that initially can produce the CR (e.g., intertrial CRs), but by being not reinforced they become partly inhibited; nevertheless, due to associations with the reinforcement, they still can produce some excitement related to it, thus facilitating the CR.     

Behavior-based safety in industry: Realizing the large-scale potential of psychology to promote human welfare

In the spirit of giving psychology away in this “Decade of Behavior,” this article reviews the behavioral science approach to preventing workplace injuries, which is currently being applied successfully in numerous companies worldwide. Unlike the traditional command-and-control approach to occupational safety, behavior-based safety (BBS) provides tools and methods employees can use to take control of their own safety performance. The author offers strategies he and his colleagues have been using for more than a decade to teach BBS to safety leaders and line workers. In addition, two conceptual models are explained. One model suggests ways to match the awareness and behavior of an individual with a particular BBS intervention technique. The second model proposes that five psychological states or “establishing conditions” increase the probability a person will use the BBS tools and procedures to actively care for the safety and health of others.     

The Probabilities of Conditionals Revisited

According to what is now commonly referred to as “the Equation” in the literature on indicative conditionals, the probability of any indicative conditional equals the probability of its consequent of the conditional given the antecedent of the conditional. Philosophers widely agree in their assessment that the triviality arguments of Lewis and others have conclusively shown the Equation to be tenable only at the expense of the view that indicative conditionals express propositions. This study challenges the correctness of that assessment by presenting data that cast doubt on an assumption underlying all triviality arguments.     

Comparing the meanings of “if” and “all”

In this study, we compared the everyday meanings of conditionals (“if p then q”) and universally quantified statements (“all p are q”) when applied to sets of elements. The interpretation of conditionals was predicted to be directly related to the conditional probability, such that P(“if p then q”) = P(q|p). Quantified statements were assumed to have two interpretations. According to an instance-focused interpretation, quantified statements are equivalent to conditionals, such that P(“all p are q”) = P(q|p). According to a set-focused interpretation, “all p are q” is true if and only if every instance in set p is an instance of q, so that the statement would be accepted when P(q|p) = 1 and rejected when this probability was below 1. We predicted an instance-focused interpretation of “all” when the relation between p and q expressed a general law for an infinite set of elements. A set-focused interpretation of “all” was predicted when the relation between p and q expressed a coincidence among the elements of a finite set. Participants were given short context stories providing information about the frequency of co-occurrence of cases of p, q, not-p, and not-q in a population. They were then asked to estimate the probability that a statement (conditional or quantified) would be true for a random sample taken from that population. The probability estimates for conditionals were in accordance with an instance-focused interpretation, whereas the estimates for quantified statements showed features of a set-focused interpretation. The type of the relation between p and q had no effect on this outcome.     

On the basis of belief in causal and diagnostic conditionals

According to the suppositional theory of conditionals, people assess their belief in a conditional statement of the form “if p then q” by conducting a mental simulation on the supposition of p in which they assess their degree of belief in q. This leads to them to the judge the probability of a conditional statement to be equal to the conditional probability, P(q|p). Evidence for this conditional probability hypothesis has been adduced in earlier studies for abstract, causal, and counterfactual conditionals. For the realistic conditionals, it is natural to assume that people perform such mental simulations by building causal mental models from prior causes to later effects. However, in the present study we show that the conditional probability hypothesis extends to diagnostic conditionals, which relate effects to causes. This new finding presents a major challenge for theoretical accounts of the mental processing of conditional statements.     

The influence of clause order,congruency, and probability on the processing of conditionals

Conditional information can be equally asserted in the forms if p, then q (e.g., “if I am ill, I will miss work tomorrow”) and q, if p (e.g., “I will miss work tomorrow, if I am ill”). While this type of clause order manipulation has previously been found to have no influence on the ultimate conclusions participants draw from conditional rules, we used self-paced reading to examine how it affects the real time incremental processing of everyday conditional statements. Experiment 1 revealed that clause order interacts with presuppositional congruency as readers hypothetically represent counterfactual statements. When if p, then q counterfactuals contained a presupposition that was incongruent with prior context, these statements took longer to read than when the presupposition was congruent, but for q, if p conditionals there was no such congruency effect. Experiment 2 revealed that reading times were influenced by the subjective probability of an indicative conditional regardless of clause order, with a penalty observed for low-probability statements relative to high-probability statements in both conditional clause orders. These data reveal a dissociation whereby clause order mediates the effect of suppositional congruency on reading times, but does not mediate the effect of subjective probability.     

On some limits of hypothetical thinking

Faced with extreme demands, hypothetical thinking runs the danger of total failure. Paradoxical propositions such as the Liar (“I am lying”) provide an opportunity to test it to its limits, while the Liar's nonparadoxical counterpart, the Truthteller (“I am telling the truth”), provides a useful comparison. Two experiments are reported, one with abstract materials (“If I am a knave then I live in Emerald City”) and one with belief-laden materials (a judge says: “If I am a knave then I enjoy pop music”). In both experiments, conditionals with Truthteller-type antecedents were “collapsed” to responses of conditional probability closely resembling estimates of control items. Liar-type antecedents, in contrast, dramatically weakened belief in conditionals in which they were embedded. The results are discussed in the framework of the theory of hypothetical thinking.     

The“response” in behavior theory

The term“response” is a basic one in behavior theory, particularly reflex theory, but its definition is not clear. The origin of the term in the common vocabulary has affected its later extensions in the analysis of behavior. Some contemporary theorists accept the existence of two“types” of response, coordinating one with the Pavlovian conditioning procedure, the other with the operant conditioning procedure of the so-called“contingent” variety. Reservations are expressed here about such distinctions between response classes and conditioning paradigms, emphasizing the difficulties that arise from certain conventions and inadequacies in current definitions and conceptions of“response.” The critical nature of the problem for behavior theory is illustrated once again by the recent laboratory finding that a familiar and accepted conditional reflex, that of the“conditioned cardiac CR,” can be fractionated into“parts” and is therefore perhaps no longer to be treated as a single unitary“response.”     

The dilution effect: Nondiagnostic information weakens the implications of diagnostic information

In a series of studies, subjects were asked to make predictions about target individuals. Some subjects were given information about the target which pretest subjects had judged to be “diagnostic”—that is, had judged to be usefully predictive of the outcome. Other subjects were given a mix of information judged to be diagnostic and information judged to be “nondiagnostic” by pretest subjects—that is, judged to be of little value for predicting the outcome. Subjects given mixed information made much less extreme predictions than did subjects given only diagnostic information. It was argued that this “dilution effect” occurs because people make predictions by making simple similarity judgments. That is, they compare the information they have about the target with their conception of outcome categories. The presence of individuating but nondiagnostic information about the target reduces the similarity between the target and those outcomes that are suggested by the diagnostic information. One of the major implications is that stereotypes and other “social knowledge structures” may be applied primarily to abstract, undifferentiated individuals and groups and may be largely set aside when judgments are made about concrete, individuated people.     

Sampling in developmental science: Situations,shortcomings, solutions,and standards

Sampling is a key feature of every study in developmental science. Although sampling has far-reaching implications, too little attention is paid to sampling. Here, we describe, discuss, and evaluate four prominent sampling strategies in developmental science: population-based probability sampling, convenience sampling, quota sampling, and homogeneous sampling. We then judge these sampling strategies by five criteria: whether they yield representative and generalizable estimates of a study’s target population, whether they yield representative and generalizable estimates of subsamples within a study’s target population, the recruitment efforts and costs they entail, whether they yield sufficient power to detect subsample differences, and whether they introduce “noise” related to variation in subsamples and whether that “noise” can be accounted for statistically. We use sample composition of gender, ethnicity, and socioeconomic status to illustrate and assess the four sampling strategies. Finally, we tally the use of the four sampling strategies in five prominent developmental science journals and make recommendations about best practices for sample selection and reporting.     

More than 50% or Less than 70% Chance: Pragmatic Implications of Single‐Bound Probability Estimates

Probability estimates can be given as ranges or uncertainty intervals, where often only one of the interval bounds (lower or upper) is specified. For instance, a climate forecast can describe La Niña as having “more than 70% chance” or “less than 90% chance” of occurring. In three experiments, we studied how research participants perceived climate‐related forecasts expressed with lower‐bound (“over X% chance”) or upper‐bound (“under Y% chance”) probability statements. Results indicate that such single‐bound statements give pragmatic information in addition to the numeric probabilities they convey. First, the studies show that these statements are directional, leading the listeners' attention in opposite directions. “Over” statements guide attention towards the possible occurrence of the event and are explained by reasons for why it might happen, while “under” statements direct attention to its possible non‐occurrence and are more often explained by reasons for why the target event might not appear, corresponding to positive (it is possible) versus negative (it is uncertain) verbal probabilities. Second, boundaries were found to reveal the forecaster's beliefs and could be perceived as indicative of an increasing or a decreasing trend. Single‐bound probability estimates are therefore not neutral communications of probability level but might “leak” information about the speaker's expectations and about past and future developments of the forecast. Copyright © 2017 John Wiley & Sons, Ltd.     

New insights on eye blindness and hand sight: Temporal constraints of visuo-motor networks

Pioneer experiments on saccadic suppression have shown that this effect is not followed by motor disorientation: Conscious perception of a target displacement can be dissociated from correct manual target reaching. It has subsequently been demonstrated that movement corrections with the same latency and spatial characteristics can be produced in conditions allowing perceptual awareness of perturbation of a target as in condition inducing saccadic suppression. In addition to the qualitative dissociation between motor performance and conscious awareness, quantitative temporal dissociations in action can be observed by manipulating different features of the visual target. When the target of an ongoing simple action is perturbed, a temporal advantage is found for responses to perturbations of location relative to colour and shape. Furthermore, there seems to be a temporal advantage for automatic motor corrections made in response to a target displacement as compared to other responses (other ongoing movement adjustments, movement interruption, conditional motor response such as pressing a key, verbal response, delayed matching-to-sample tasks). Thus, this paper reviews evidence for the fact that the temporal characteristics of any given response to a stimulus are dependent both on the sensory processes and on the type of response generated. Accordingly, identification responses (such as verbal report) to a visual stimulus are much slower than motor corrections of an ongoing movement in response to a target location change because of different processing times of the stimulus features (“What” compared to “Where”) and of the response itself (“What” compared to “How”). The existence of two continua (What/Where and What/How) is proposed between these two extreme stimulus- response combinations. This model may be a useful framework to better understand visuo-motor transformations and the network of connections between visual and motor areas.     

Measuring single-item identification efficiencies for letters and 3-D objects

Identification thresholds and the corresponding efficiencies (ideal/human thresholds) are typically computed by collapsing data across an entire stimulus set within a given task in order to obtain a “multiple-item” summary measure of information use. However, some individual stimuli may be processed more efficiently than others, and such differences are not captured by conventional multiple-item threshold measurements. Here, we develop and present a technique for measuring “single-item” identification efficiencies. The resulting measure describes the ability of the human observer to make use of the information provided by a single stimulus item within the context of the larger set of stimuli. We applied this technique to the identification of 3-D rendered objects (Exp. 1) and Roman alphabet letters (Exp. 2). Our results showed that efficiency can vary markedly across stimuli within a given task, demonstrating that single-item efficiency measures can reveal important information that is lost by conventional multiple-item efficiency measures.     

On Terrorism and the Politics of Compulsion

The concept of “terrorism” is problematized and argued to be at one end of a continuum of behavior that can be characterized as “compulsion.” This approach to conflict is explained in terms of Transactional Analysis and the inadequacy of compulsion as a means of managing human affairs (politics) is explored in relation to the use of power that it requires, and to the responses it generates. An alternative behavior, based on “turning the other cheek” and Satyagraha (confronting), is advocated in the expectation that it will prove more fruitful in managing conflict and reducing terrorist outrages.     

Sequential analysis as a method of feedback for family therapy process

Abstract

The purpose of this study was to examine the relationship between therapist verbal behavior and family cooperation and resistance during the second session of family therapy with juvenile delinquents. Sequential analysis was used to investigate the impact of one therapist's behavior on family resistance and cooperation in a sample of 12 families. The results of the sequential analysis revealed that therapist “support” and “teach” behaviors were associated with significant increases in the likelihood of family cooperation. The study provides an example of how sequential analysis can be used to inform family therapists about the impact of their behavior on families.     

The Probability of Iterated Conditionals

Iterated conditionals of the form If p, then if q, r are an important topic in philosophical logic. In recent years, psychologists have gained much knowledge about how people understand simple conditionals, but there are virtually no published psychological studies of iterated conditionals. This paper presents experimental evidence from a study comparing the iterated form, If p, then if q, r with the “imported,” noniterated form, If p and q, then r, using a probability evaluation task and a truth‐table task, and taking into account qualitative individual differences. This allows us to critically contrast philosophical and psychological approaches that make diverging predictions regarding the interpretation of these forms. The results strongly support the probabilistic Adams conditional and the “new paradigm” that takes this conditional as a starting point.