Psychology, epistemology, and skepticism in Hume’s argument about induction

Since the mid-1970s, scholars have recognized that the skeptical interpretation of Hume’s central argument about induction is problematic. The science of human nature presupposes that inductive inference is justified and there are endorsements of induction throughout Treatise Book I. The recent suggestion that I.iii.6 is confined to the psychology of inductive inference cannot account for the epistemic flavor of its claims that neither a genuine demonstration nor a non-question-begging inductive argument can establish the uniformity principle. For Hume, that inductive inference is justified is part of the data to be explained. Bad argument is therefore excluded as the cause of inductive inference; and there is no good argument to cause it. Does this reinstate the problem of induction, undermining Hume’s own assumption that induction is justified? It does so only if justification must derive from “reason”, from the availability of a cogent argument. Hume rejects this internalist thesis; induction’s favorable epistemic status derives from features of custom, the mechanism that generates inductive beliefs. Hume is attracted to this externalist posture because it provides a direct explanation of the epistemic achievements of children and non-human animals—creatures that must rely on custom unsupplemented by argument.     

An algebra of human concept learning

An important element of learning from examples is the extraction of patterns and regularities from data. This paper investigates the structure of patterns in data defined over discrete features, i.e. features with two or more qualitatively distinct values. Any such pattern can be algebraically decomposed into a spectrum of component patterns, each of which is a simpler or more atomic “regularity.” Each component regularity involves a certain number of features, referred to as its degree. Regularities of lower degree represent simpler or more coarse patterns in the original pattern, while regularities of higher degree represent finer or more idiosyncratic patterns. The full spectral breakdown of a pattern into component regularities of minimal degree, referred to as its power series, expresses the original pattern in terms of the regular rules or patterns it obeys, amounting to a kind of “theory” of the pattern. The number of regularities at various degrees necessary to represent the pattern is tabulated in its power spectrum, which expresses how much of a pattern's structure can be explained by regularities of various levels of complexity. A weighted mean of the pattern's spectral power gives a useful numeric summary of its overall complexity, called its algebraic complexity. The basic theory of algebraic decomposition is extended in several ways, including algebraic accounts of the typicality of individual objects within concepts, and estimation of the power series from noisy data. Finally some relations between these algebraic quantities and empirical data are discussed.     

儿童4岁时自我延迟满足能力对其9岁时学校社会交往能力预期的追踪

采用追踪研究,用实验室实验和情境观察相结合的方法考察了54名儿童4岁时的自我延迟满足能力,5年后结合教师访谈与评定、同伴提名、儿童自评等方法综合评定这些儿童9岁时的学校社会交往能力,探讨儿童4岁时自我延迟满足能力对其9岁时学校社会交往能力的预期作用。结果表明：儿童4岁时的自我延迟满足能力水平可以预期其9岁时的学校社会交往能力水平。4岁时自我延迟满足能力高的儿童在9岁时的学校社会交往能力总体发展也好,其遵守规则与执行任务能力、与教师交往能力、与同伴交往能力、社交情绪发展水平都显著高于那些在4岁时自我延迟满足能力低的儿童;反之则差     

The effects of signaling stimulus presentation during noncontingent reinforcement

The effects of signaling the return of items or attention during treatment with noncontingent reinforcement were examined. First, functional analyses showed that the problem behavior exhibited by 2 teenagers with developmental disabilities was sensitive to social positive reinforcement. Next, delivery of the stimulus that maintained problem behavior on a fixed-time (FT) schedule was compared to a condition in which the removal of the stimulus during the same FT schedule was immediately preceded by a statement indicating that the stimulus would be returned and the initiation of a digital timer. Results show that the FT schedule reduced problem behavior, and the addition of an informative statement and a timer further decreased problem behavior.     

The fine-grained metaphysics of artifactual and biological functional kinds

In this paper we consider the emerging position in metaphysics that artifact functions characterize real kinds of artifacts. We analyze how it can circumvent an objection by David Wiggins (Sameness and substance renewed, 2001, 87) and then argue that this position, in comparison to expert judgments, amounts to an interesting fine-grained metaphysics: taking artifact functions as (part of the) essences of artifacts leads to distinctions between principles of activity of artifacts that experts in technology have not yet made. We show, moreover, that our argument holds not only in the artifactual realm but also in biology: taking biological functions as (part of the) essences of organs leads to distinctions between principles of activity of organs that biological experts have not yet made. We run our argument on the basis of analyses of artifact and biological functions as developed in philosophy of technology and of biology, thus importing results obtained outside of metaphysics into the debate on ontological realism. In return, our argument shows that a position in metaphysics provides experts reason for trying to detect differences between principles of activities of artifacts and organs that have not been detected so far.     

Delay, Probability, and Social Discounting in A Public Goods Game

A human social discount function measures the value to a person of a reward to another person at a given social distance. Just as delay discounting is a hyperbolic function of delay, and probability discounting is a hyperbolic function of odds-against, social discounting is a hyperbolic function of social distance. Experiment 1 obtained individual social, delay, and probability discount functions for a hypothetical $75 reward; participants also indicated how much of an initial $100 endowment they would contribute to a common investment in a public good. Steepness of discounting correlated, across participants, among all three discount dimensions. However, only social and probability discounting were correlated with the public-good contribution; high public-good contributors were more altruistic and also less risk averse than low contributors. Experiment 2 obtained social discount functions with hypothetical $75 rewards and delay discount functions with hypothetical $1,000 rewards, as well as public-good contributions. The results replicated those of Experiment 1; steepness of the two forms of discounting correlated with each other across participants but only social discounting correlated with the public-good contribution. Most participants in Experiment 2 predicted that the average contribution would be lower than their own contribution.     

The Hypothetical Syllogism

The hypothetical syllogism is invalid in standard interpretations of conditional sentences. Many arguments of this sort are quite compelling, though, and you can wonder what makes them so. I shall argue that it is our parsimony in regard to connections among events and states of affairs. All manner of things just might, for all we know, be bound up with one another in all sorts of ways. But ordinarily it is better, being simpler, to assume they are unconnected. In so doing, we jump to the conclusions of some compelling but invalid arguments.     

海洛因延迟强化物超快速折扣倾向的心理机制

以124名处于不同戒除时相的男性海洛因戒除者为被试, 采用金钱和海洛因延迟折扣任务(DDT), 并以基于线索暴露的渴求感测量为效度指标, 探讨了该类人群对海洛因延迟强化超快速折扣倾向及其心理机制。结果发现: (1) 相对于金钱延迟强化, 戒除者对海洛因延迟强化表现出显著的超快速折扣倾向, 且该倾向不随戒除期的延长而改变; (2) 戒除者对海洛因延迟强化的超快速折扣行为可能是其冲动性特质与海洛因相关线索共同作用的结果, 海洛因相对于金钱折扣率的增量部分可能反映了海洛因及其相关线索对该类人群主观渴求感的诱发效应。     

简算策略教学提高小学四年级儿童的计算水平及延迟效应

采用3组平衡组实验设计对小学四年级171名学生进行教学实验,两组实验班学生分别采用讲授式和探究式教学方法进行简算策略计算教学,对照班教师自主进行计算教学。结果揭示：通过专门开设简算策略教学训练课,实验班学生的的计算成绩、计算速度和计算兴趣显著高于对照班学生;实验班的延迟提示与不提示测验无显著差异,未出现策略“利用性缺陷”现象;讲授式和探究式教学方法进行策略教学的效果无明显差异。本研究表明：专门开设策略训练课能提高学生的计算水平和学习兴趣,是有效的和必要的;只要教学方法得当,策略“利用性缺陷”可以避免     

Stimuli inevitably generated by behavior that avoids electric shock are inherently reinforcing.

A molecular analysis based on the termination of stimuli that are positively correlated with shock and the production of stimuli that are negatively correlated with shock provides a parsimonious count for both traditional discrete-trial avoidance behavior and the data derived from more recent free-operant procedures. The necessary stimuli are provided by the intrinsic feedback generated by the subject's behavior, in addition to those presented by the experimenter. Moreover, all data compatible with the molar principle of shock-frequency reduction as reinforcement are also compatible with a delay-of-shock gradient, but some data compatible with the delay gradient are not compatible with frequency reduction. The delay gradient corresponds to functions relating magnitude of behavioral effect to the time between conditional and unconditional stimuli, the time between conditioned and primary reinforcers, and the time between responses and positive reinforcers.