This is a review article of Paul Cillier's 1999 book _Complexity and Postmodernism_. The review article is generally encouraging and constructive, although isolates a number of areas in need of clarification or development in Cillier's work. The volume of the _South African Journal of Philosophy_ in which the review article appeared also printed a response by Cilliers.
[A slightly revised version of this paper has been accepted by the BJPS] More attention has been devoted to providing evolutionary scenarios accounting for the development of beliefs, or belief-like states, than for desires or preferences. Here I articulate and defend an evolutionary rationale for the development of psychologically real preference states. Preferences token or represent the expected values of discriminated states, available actions, or action-state pairings. The argument is an application the ‘environmental complexity thesis’ found in Godfrey-Smith and Sterelny, (...) although my conclusions differ from Sterelny’s. I argue that tokening expected utilities can, under specified general conditions, be a powerful design solution to the problem of allocating the capacities of an agent in an efficient way. Preferences are for efficient action selection, and are a ‘fuel for success’ in the sense urged by Godfrey-Smith for true beliefs. They will tend to be favoured by selection when environments are complex in ways that matter to an organism, and when organisms have rich behavioural repertoires with heterogenous returns and costs. The rationale suggested here is conditional, especially on contingencies in what design options are available to selection and on trade-offs associated with the costs of generating and processing representations of value. The unqualified efficiency rationale for preferences suggests that organisms should represent expected utilities in a comprehensive and consistent way, but none of them do. In the final stages of the paper I consider some of the ways in which design trade-offs compromise the implementation of preferences in organisms that have them. (shrink)
We discuss Russell's 1913 essay arguing for the irrelevance of the idea of causation to science and its elimination from metaphysics as a precursor to contemporary philosophical naturalism. We show how Russell's application raises issues now receiving much attention in debates about the adequacy of such naturalism, in particular, problems related to the relationship between folk and scientific conceptual influences on metaphysics, and to the unification of a scientifically inspired worldview. In showing how to recover an approximation to Russell's conclusion (...) while explaining scientists' continuing appeal to causal ideas (without violating naturalism by philosophically correcting scientists) we illustrate a general naturalist strategy for handling problems around the unification of sciences that assume different levels of naïveté with respect to folk conceptual frameworks. We do this despite rejecting one of the premises of Russell's argument, a version of reductionism that was scientifically plausible in 1913 but is not so now. (shrink)
A recurring claim in a number of behavioural, cognitive and neuro-scientific literatures is that there is, or must be, a unidimensional ‘common currency’ in which the values of different available options are represented. There is striking variety in the quantities or properties that have been proposed as determinants of the ordering in motivational strength. Among those seriously suggested are pain and pleasure, biological fitness, reward and reinforcement, and utility among economists, who have regimented the notion of utility in a variety (...) of ways, some of them incompatible. This topic deserves philosophical attention for at least the following reasons. Repeated invocation of the ‘common currency’ idiom isn’t merely terminological coincidence because most of the claims are competing explanations either of manifest pattern in choices, or of order in the processes producing choice. We can’t suppose that the different currency claims within each area are compatible, because there are significant obstacles to identifying pairs of members of either the ‘pattern’ or ‘process’ group. There are, finally, seriously opposed positions about the relationships between the pattern facts and the process facts. There are philosophical positions both favouring and opposing a common currency. But direct consideration of the abstract relationships between claims about common currencies across scientific settings, and the arguments for and against these claims, is relatively rare. There is, though, much of philosophical interest to be found here. (shrink)
A wave of recent work in metaphysics seeks to undermine the anti-reductionist, functionalist consensus of the past few decades in cognitive science and philosophy of mind. That consensus apparently legitimated a focus on what systems do, without necessarily and always requiring attention to the details of how systems are constituted. The new metaphysical challenge contends that many states and processes referred to by functionalist cognitive scientists are epiphenomenal. It further contends that the problem lies in functionalism itself, and that, to (...) save the causal significance of mind, it is necessary to re-embrace reductionism. We argue that the prescribed return to reductionism would be disastrous for the cognitive and behavioral sciences, requiring the dismantling of most existing achievements and placing intolerable restrictions on further work. However, this argument fails to answer the metaphysical challenge on its own terms. We meet that challenge by going on to argue that the new metaphysical skepticism about functionalist cognitive science depends on reifying two distinct notions of causality (one primarily scientific, the other metaphysical), then equivocating between them. When the different notions of causality are properly distinguished, it is clear that functionalism is in no serious philosophical trouble, and that we need not choose between reducing minds or finding them causally impotent. The metaphysical challenge to functionalism relies, in particular, on a naïve and inaccurate conception of the practice of physics, and the relationship between physics and metaphysics. Key Words: explanation; functionalism; mental causation; metaphysics; reductionism. (shrink)
Parts of the genome of a single individual can have conflicting interests, depending on which parent they were inherited from. One mechanism by which these conflicts are expressed in some taxa, including mammals, is genomic imprinting, which modulates the level of expression of some genes depending on their parent of origin. Imprinted gene expression is known to affect body size, brain size, and the relative development of various tissues in mammals. A high fraction of imprinted gene expression occurs in the (...) brain. Biologists including Hamilton, Trivers and Haig have proposed that this may explain some intrapersonal conflict in humans. This speculation amounts to an inference from conflict within the genome to conflict within the brain or mind. This is a provocative proposal, which deserves serious attention. In this paper I assess aspects of Haig’s version of the proposal. I argue, first, that the notion that intragenomic conflict predicts personal inconsistency should be rejected. Second, while it is unlikely that it credibly predicts sub-personal agents representing conflicting genetic interests, it is plausible that it predicts that the division of cognitive labour could be exploited to turn sub-systems into proxies for conflicting interests. (shrink)
Our response amplifies our case for scientific realism and the unity of science and clarifies our commitments to scientific unity, nonreductionism, behaviorism, and our rejection of talk of “emergence.” We acknowledge support from commentators for our view of physics and, responding to pressure and suggestions from commentators, deny the generality supervenience and explain what this involves. We close by reflecting on the relationship between philosophy and science.
Recent scientific findings about human decision making would seem to threaten the traditional concept of the individual conscious will. The will is threatened from "below" by the discovery that our apparently spontaneous actions are actually controlled and initiated from below the level of our conscious awareness, and from "above" by the recognition that we adapt our actions according to social dynamics of which we are seldom aware. In Distributed Cognition and the Will, leading philosophers and behavioral scientists consider how much, (...) if anything, of the traditional concept of the individual conscious will survives these discoveries, and they assess the implications for our sense of freedom and responsibility. The contributors all take science seriously, and they are inspired by the idea that apparent threats to the cogency of the idea of will might instead become the basis of its reemergence as a scientific subject. They consider macro-scale issues of society and culture, the micro-scale dynamics of the mind/brain, and connections between macro-scale and micro-scale phenomena in the self-guidance and self-regulation of personal behavior. Contributors: George Ainslie, Wayne Christensen, Andy Clark, Paul Sheldon Davies, Daniel C. Dennett, Lawrence A. Lengbeyer, Dan Lloyd, Philip Pettit, Don Ross, Tamler Sommers, Betsy Sparrow, Mariam Thalos, Jeffrey B. Vancouver, Daniel M. Wegner, Tadeusz W. ZawidzkiDon Ross is Professor of Philosophy and Professor of Finance, Economics, and Quantitative Methods at the University of Alabama at Birmingham and Professor of Economics at the University of Cape Town, South Africa. David Spurrett is Professor of Philosophy at the Howard College Campus of the University of KwaZulu-Natal, South Africa. Harold Kincaid is Professor and Chair of the Department of Philosophy and Director of the Center for Ethics and Values in the Sciences at the University of Alabama at Birmingham. G. Lynn Stephens is Professor of Philosophy at the University of Alabama at Birmingham. (shrink)
Cartwright attempts to argue from an analysis of the composition of forces, and more generally the composition of laws, to the conclusion that laws must be regarded as false. A response to Cartwright is developed which contends that properly understood composition poses no threat to the truth of laws, even though agreeing with Cartwright that laws do not satisfy the "facticity" requirement. My analysis draws especially on the work of Creary, Bhaskar, Mill, and points towards a general rejection of Cartwright's (...) view that laws, especially fundamental laws, should be seen as false. (shrink)
Bas van Fraassen claims that materialism involves false consciousness. The thesis that matter is all that there is, he says, fails to rule out any kinds of theories. The false consciousness consists in taking materialism to be cognitive rather than an existential stance, or attitude, of deference to the current content of science in matters of ontology, and a favourable attitude to completeness claims about the content of science at a time. The main argument Van Fraassen provides for saying that (...) materialism is not cognitive is an account according to which materialism has responded, so far, to changes in science by abandoning previous hallmarks of the material, and accepting new ones instead of by taking materialism to have been refuted. I argue that van Fraassen’s conclusions run far ahead of what his arguments establish. The fact of revision and revolution in the history of science, and the undoubted provisionality and incompleteness of science as we have it, do indeed tell against simply letting current science determine what the physical is for philosophical purposes. But the alternative to betting on current science need not be unconditional open-endedness. The changes that materialists have accepted so far do not, furthermore, support the false consciousness interpretation. The reason for this is not that materialists will swallow anything, but rather that the changes accepted are consistent with the truth of materialism when appropriately characterized. (shrink)
Sterelny (2003) develops an idealised natural history of folk-psychological kinds. He argues that belief-like states are natural elaborations of simpler control systems, called detection systems, which map directly from environmental cue to response. Belief-like states exhibit robust tracking (sensitivity to multiple environmental states), and response breadth (occasioning a wider range of behaviours). The development of robust tracking and response-breadth depend partly on properties of the informational environment. In a transparent environment the functional relevance of states of the world is directly (...) detectable. Outside transparent environments, selection can favour decoupled representations. Sterelny maintains that these arguments do not generalise to desire. Unlike the external environment, the internal processes of an organism, he argues, are selected for transparency. Parts of a single organism gain nothing from deceiving one another, but gain significantly from accurate signalling of their states and needs. Key conditions favouring the development of belief-like states are therefore absent in the case of desires. Here I argue that Sterelny’s reasons for saying that his treatment of belief does not generalise to motivation (desires, or preferences) are insufficient. There are limits to the transparency that internal environments can achieve. Even if there were not, tracking the motivational salience of external states suggests possible gains for systematic tracking of outcome values in any system in which selection has driven the production of belief-like states. (shrink)
A striking feature of the latest version of Dennett’s ‘big picture’ of the evolution of life and mind is frequent reference to ‘affordances’. An affordance is, roughly, a possibility for action for a creature in an environment. Given more than one possibility for action, a good question is: what will the creature actually do? I argue that affordances pose a problem of selection, and that a good general solution to this problem of mind-design is to implement a system of preferences.
This chapter applies the parity principle in discussing “active externalism,” which claims that the mind need not be confined within either the brain or body. Consequently, how one brain or body interacts with other brains and bodies must be explored, together with the problems that may arise out of this interaction. This chapter is not concerned with beliefs and desires as mental states but whether they play a role in controlling behavior. It argues the notion that any course of action (...) considered part of the cognitive process going on inside the brain is still part of the cognitive process no matter where it is being implemented. Divided into two parts, this chapter first establishes some points of reference regarding language and cognition, and then proceeds to an attempt to connect the issues by directly discussing the parity principle. (shrink)
Philosophers and behavioral scientists discuss what, if anything, of the traditionalconcept of individual conscious will can survive recent scientific discoveries that humandecision-making is distributed across different brain processes and ...
This paper concerns the question of how to specify what is to count as physical for the purposes of debates concerning either physicalism or the completeness of physics. I argue that what is needed from an account of the physical depends primarily on the particular issue at stake, and that the demand for a general a priori speciﬁcation of the physical is misplaced. A number of attempts to say what should be counted as physical are defended from recent attacks by (...) Chris Daly, and a speciﬁc proposal due to David Papineau developed and extended. I argue that this approach is more than suitable for the debates for which it is intended. (shrink)
Bhaskar's articulation of his ‘transcendental realism' includes an argument for a form of causal emergence which would mean the rejection of physicalism, by means of rejecting the causal closure of the physical. His argument is based on an analysis of the conditions for closure, where closed systems manifest regular or Humean relations between events. Bhaskar argues that the project of seeking closure entails commitment to a strong reductionism, which in turn entails the impossibility of science itself, and concludes that we (...) should endorse causal emergence. I argue that Bhaskar's case grossly overreaches itself, and that he fails to establish the emergentist conclusions which he asserts. Consequently his programme poses no significant threat to physicalism. (shrink)
The status of fundamental laws is an important issue when deciding between the three broad ontological options of fundamentalism (of which the thesis that physics is complete is typically a sub-type), emergentism, and disorder or promiscuous realism. Cartwrights assault on fundamental laws which argues that such laws do not, and cannot, typically state the facts, and hence cannot be used to support belief in a fundamental ontological order, is discussed in this context. A case is made in defence of a (...) moderate form of fundamentalism, which leaves open the possibility of emergentism, but sets itself against the view that our best ontology is disordered. The argument, taking its cue from Bhaskar, relies on a consideration of the epistemic status of experiments, and the question of the possible generality of knowledge gained in unusual or controlled environments. (shrink)
More attention has been devoted to providing evolutionary accounts of the development of beliefs, or belief-like states, than for desires or preferences. Here I articulate and defend an evolutionary rationale for the development of psychologically real preference states. Preferences token or represent the expected values available actions given discriminated states of world and agent. The argument is an application of the ‘environmental complexity thesis’ found in Godfrey-Smith and Sterelny, although my conclusions differ from Sterelny’s. I argue that tokening expected utilities (...) can, under specified general conditions, be a powerful design solution to the problem of efficiently allocating the capacities of an agent. Preferences are for efficient action selection, and count as a ‘fuel for success’ in the sense urged by Godfrey-Smith for true beliefs. They will tend to be favoured by selection when environments are complex in ways that matter to an organism, and when organisms have large behavioural repertoires with heterogeneous returns and costs.The rationale suggested here is conditional, especially on contingencies in what design options are available to selection and on trade-offs associated with the costs of generating and processing representations of value. The unqualified efficiency rationale for preferences suggests that organisms should represent expected utilities in a comprehensive and consistent way, but none of them do. In the final stages of the paper I consider some of the ways design trade-offs compromise the implementation of preferences in organisms that have them. (shrink)
From a certain simplistic and inaccurate, although regrettably popular, perspective philosophy, at least for the past few decades, is available only in two main flavours – analytic and continental. Some self-identified members of both camps are apt to endorse uncharitable caricatures of what the others are up to. Among the many lines of criticism that can be directed against this false dichotomy, I wish to focus on discussion of a broadly naturalistic orientation that rejects many of the commitments both of (...) paradigmatic analytic philosophy and paradigmatic continental philosophy. For the committed naturalist, the enterprise of philosophy is continuous with that of systematic empirical enquiry into the workings of the world . From a naturalistic perspective many of the standard moves of analytic philosophy, such as testing a proposal against ‘intuitions’, are as preposterous as the claims of ‘continental’ and ‘analytic’ philosophers sometimes appear to one another. (shrink)
This paper concerns the question of how to specify what is to count as physical for the purposes of debates concerning either physicalism or the completeness of physics. I argue that what is needed from an account of the physical depends primarily on the particular issue at stake, and that the demand for a general a priori specification of the physical is misplaced. A number of attempts to say what should be counted as physical are defended from recent attacks by (...) Chris Daly, and a specific proposal due to David Papineau developed and extended. I argue that this approach is more than suitable for the debates for which it is intended. (shrink)
The present work is focussed on the completeness of physics, or what is here called the Completeness Thesis: the claim that the domain of the physical is causally closed. Two major questions are tackled: How best is the Completeness Thesis to be formulated? What can be said in defence of the Completeness Thesis? My principal conclusions are that the Completeness Thesis can be coherently formulated, and that the evidence in favour if it significantly outweighs that against it. In opposition to (...) those who argue that formulation is impossible because no account of what is to count as physical can be provided, I argue that as long as the purpose of the argument in which the account is to be used are borne in mind there are no significant difficulties. The account of the physical which I develop holds as physical whatever is needed to fix the likelihood of pre-theoretically given physical effects, and hypothesises in addition that no chemical, biological or psychological factors will be needed in this way. The thus formulated Completeness Thesis is coherent, and has significant empirical content. In opposition to those who defend the doctrine of emergentism by means of philosophical arguments I contend that those arguments are flawed, setting up misleading dichotomies between needlessly attenuated alternatives and assuming the truth of what is to be proved. Against those who defend emergentism by appeal to the evidence, I argue that the history of science since the nineteenth century shows clearly that the empirical credentials of the view that the world is causally closed at the level of a small number of purely physical forces and types of energy is stronger than ever, and the credentials of emergentism correspondingly weaker. In opposition to those who argue that difficulties with reductionism point to the implausibility of the Completeness Thesis I argue that completeness in no way entails the kinds of reductionism which give rise to the difficulties in question. I argue further that the truth of the Completeness Thesis is in fact compatible with a great deal of taxonomic disorder and the impossibility of any general reduction of non-fundamental descriptions to fundamental ones. In opposition to those who argue that the epistemological credentials of fundamental physical laws are poor, and that those laws should in fact be seen as false, I contend that truth preserving accounts of fundamental laws can be developed. Developing such an account, I test it by considering cases of the composition of forces and causes, where what takes place is different to what is predicted by reference to any single law, and argue that viewing laws as tendencies allows their truth to be preserved, and sense to be made of both the experimental discovery of laws, and the fact that composition enables accurate prediction in at least some cases. (shrink)
A literature in which most data are outliers is flawed, and the target article sounds a timely alarm call for the behavioural sciences. It also suggests remedies. We mostly concur, except for arguing that the importance of the fact that the researchers themselves are mostly outliers has been underplayed. Improving matters requires non-Western researchers, as well as research subjects.
David Benatar has argued that the coming into existence of a sentient being is always a harm, and consequently that people who have children always do wrong. The most natural objection maintains that in many lives (at least) while there is some pain, there are also goods (including pleasures) that can outweigh the suffering. From Benatar’s perspective this move, while possibly useful in assessing the lives of those who actually exist, is not an effective defence of procreation. In the case (...) of people who do not yet exist, he maintains that there is a crucial asymmetry arising from the putative fact that the absence of pain is good even if that good is not enjoyed by anyone, whereas absence of pleasure is not bad unless there is somebody for whom that absence is a deprivation. For the potentially existing, he concludes, preventing the pain of existence is justified, but not so facilitating enjoyment of its pleasures. I argue that the asymmetry is insufficiently motivated. I also sketch two additional lines of argument against the asymmetry. First, it may not include all relevant factors. Second, plausible duties to prevent pain require possible sufferers, but do not apply straightforwardly when extended to include preventing the sufferers themselves. (shrink)
Empiricism: reloaded Content Type Journal Article Category Book Review Pages 1-4 DOI 10.1007/s11016-012-9652-7 Authors David Spurrett, University of KwaZulu-Natal, Howard College Campus, Durban, 4041 South Africa Journal Metascience Online ISSN 1467-9981 Print ISSN 0815-0796.
Causal exclusion arguments, especially as championed by Kim, have recently made life uncomfortable for would-be non-reductive physicalists. Non-reductive physicalism was itself, in turn, partly a response to earlier arguments against reductionism. The philosophy of science, though, distinguishes more forms of reduction than philosophy of mind generally cares to. In this paper I review four major families of reductionist thesis, and give reasons for keeping them more carefully separate than usual. South African Journal of Philosophy Vol. 25(2) 2006: 159-171.
General systems for reciprocity explain the same phenomena as the target article's proposed revenge system, and can explain other cooperative phenomena. We need more reason to hypothesise a specific revenge system. In addition, the proposed calculus of revenge is less sensitive to absolute magnitudes of revenge than it should be.
There has been lively recent debate over the value of appeals to intuitions in philosophy. Some, especially ‘experimental philosophers’, have argued that such appeals can carry little or no evidential weight, and that standard analytic philosophy is consequently methodologically bankrupt. Various defences of intuitions, and analytic philosophy, have also been offered. In this paper I review the case against intuitions, in particular the claims that intuitions vary with culture, and are built by natural selection, and argue that much of their (...) force depends on assuming that the required sense of intuition is of a kind of human universal. In opposition to this view I argue that there is reason to regard intuitions of professional philosophers as parochial developmental achievements (so that cultural variation among non-professionals is irrelevant) and also the product of a training process that warrants ascribing some evidential weight to them. The argument made here is not anti-naturalistic, nor does it grant intuitions any special or trumping evidential status. Unlike some defences of analytic philosophy it does not depend on denying that philosophers appeal to intuitions at all. (shrink)
Reason aims at truth, so normative considerations are a proper part of the study of reasoning. Excluding them means neglecting some of what we know or can discover about reasoning. Also, the normativist position we are asked to reject by Elqayam & Evans (E&E) is defined in attenuated and self-contradictory ways.
Shanker & King (S&K) trumpet the adoption of a “new paradigm” in communication studies, exemplified by ape language research. Though cautiously sympathetic, I maintain that their argument relies on a false dichotomy between “information” and “dynamical systems” theory, and that the resulting confusion prevents them from recognizing the main chance their line of thinking suggests.
According to various theorists and empirical scholars of behavior and decision, including economists, utility theorists, behavioral ecologists, behavioral economists and researchers in the new field of neuroeconomics the value (typically understood as utility) of competing choices must be represented on a common scale in order for them to count as competing at all, and in order for orderly comparison to lead to actual choices. For some neuroeconomists this means that expected (cardinal) utilities are neurally represented by firing rates of cells (...) in specific brain regions. In this paper some important statements of the ‘common currency’ argument are reviewed and critically examined. A rational reconstruction of the key argument is then subject to criticism informed by a variety of empirical and theoretical considerations. In a strong form it does not survive the criticism, and this fact points the way to a re-examination of the sense in which complex living systems, including people, are agents in any straightforward sense. (shrink)
I present reasons for adding an embodiment criterion to the list defended by Anderson & Lebiere (A&L). I also entertain a likely objection contending that embodiment is merely a type of dynamic behavior and is therefore covered by the target article. In either case, it turns out that neither connectionism nor ACT-R do particularly well when it comes to embodiment.
Our point of departure is Russell’s (1913) argument for the ‘complete extrusion’ of the word ‘cause’ from the philosophical vocabulary. We argue that at least three different types of philosophical project concerning ‘cause’ should be carefully distinguished, and that failures to distinguish them lie at the root of some apparently recalcitrant problems. We call them the ‘cognitive’, the ‘scientific’ and the ‘metaphysical’.
Knobe relies on unhelpful analogies in stating his main thesis about the mind. It isn't clear what saying the mind works, or doesn't work, or means. We suggest he should say that some think that human cognition respects a ban on fallacies of relevance, where considerations actually irrelevant to truth are taken as evidence. His research shows that no such ban is respected.
Supporters of Ainslie's model face questions about its integration with neuroscience. Although processes of value estimation may well turn out to be locally implemented, methodological reasons suggest this is less likely in the case of subpersonal “interests.”.
This inaugural lecture was delivered at the Howard College Campus of UKZN on 2 April 2008. In it I do three things. First I sketch some arguments in favour of a naturalist conception of philosophy. The conclusions that I’m after are that philosophy is not an autonomous enterprise, so that it had better be continuous with scientific enquiry if it is to get anywhere. A supplementary claim I defend briefly is that the natural and social sciences should be viewed as (...) more integrated than they usually are. Second, I offer some reasons for rejecting all identifiable forms of social constructivism about knowledge. Finally, I say something about what ‘African Scholarship’ might mean, given the preceding considerations. There I briefly defend the claim that there is no epistemically interesting sense in which there is such a thing as African knowledge. (shrink)
The interests of mother and infants do not exactly coincide. Further, infants are not merely objects of attempted control by mothers, but the sources of attempts to control what mothers do. Taking account of the ways in which this is so suggests an enriched perspective on mother-infant interaction and on the beginnings of conventionalized signaling.
Lea & Webley's (L&W's) non-exclusive distinction between tool-like and drug-like motivators is insufficiently discriminating to say much about money that is useful, as the distinction's equivocal application to sex, food, and drugs shows. Further, it appears as though the motivations of problem gamblers are non-metaphorically like those of drug addicts. (Published Online April 5 2006).
People differ in the extent to which they discount the values of future rewards. Behavioural economists measure these differences in terms of functions that describe rates of reduced valuation in the future – temporal discounting – as these vary with time. They measure differences in preference for risk – differing rates of probability discounting – in terms of similar functions that describe reduced valuation of rewards as the probability of their delivery falls. So-called ‘impulsive’ people, including people disposed to addiction, (...) tend to choose rewards in patterns that are described by unusually steeply sloped discount functions. The empirical literature is ambivalent as to whether this applies to pathological gamblers (PGs) who manifest most other behavioural patterns associated with addiction, with different, equally careful studies suggesting opposite conclusions (Petry & Casarella 1999; Holt, Green & Myerson 2003). This puzzle may arise from the fact that most previous experiments on discounting behaviour were not designed so as to allow effects of high temporal discounting to be distinguished from effects of low probability discounting. (Addiction has sometimes been associated with the latter because it seems to involve, at least in the starting addict, under appreciation of risk.) Our research project investigates both forms of discounting behaviour and their relationship to severity of risk of PG in a community sample of South African gamblers. (shrink)