Understanding jumping to conclusions in patients with persecutory delusions: working memory and intolerance of uncertainty

Background. Persecutory delusions are a key psychotic experience. A reasoning style known as ‘jumping to conclusions’ (JTC) – limited information gathering before reaching certainty in decision making – has been identified as a contributory factor in the occurrence of delusions. The cognitive processes that underpin JTC need to be determined in order to develop effective interventions for delusions. In the current study two alternative perspectives were tested: that JTC partially results from impairment in information-processing capabilities and that JTC is a motivated strategy to avoid uncertainty.Method. A group of 123 patients with persistent persecutory delusions completed assessments of JTC (the 60:40 beads task), IQ, working memory, intolerance of uncertainty, and psychiatric symptoms. Patients showing JTC were compared with patients not showing JTC.Results. A total of 30 (24%) patients with delusions showed JTC. There were no differences between patients who did and did not jump to conclusions in overall psychopathology. Patients who jumped to conclusions had poorer working memory performance, lower IQ, lower intolerance of uncertainty and lower levels of worry.Working memory and worry independently predicted the presence of JTC.Conclusions. Hasty decision making in patients with delusions may partly arise from difficulties in keeping information in mind. Interventions for JTC are likely to benefit from addressing working memory performance, while in vivo techniques for patients with delusions will benefit from limiting the demands on working memory. The study provides little evidence for a contribution to JTC from top down motivational beliefs about uncertainty

The perseveration of checking thoughts and mood–as–input hypothesis

This paper describes two experiments designed to investigate how a current model of task perseveration, the mood-as-input hypothesis, might be applied to activities relevant to compulsive checking. The mood-as-input hypothesis predicts that perseveration at an open-ended task will be determined by a combination of the “stop rules” adopted for the task, and the valency of the mood state in which the task is conducted. Experiment 1 required participants to generate items that should be checked for safety/security if they were leaving their home unattended. Experiment 2 used an analogue recall task, in which participants were asked to recall items from a comprehensive list of items that should be checked if they were to leave their home safe/secure. Both experiments found that perseveration at the tasks was determined by particular configurations of mood and stop rules for the task. Of most relevance to compulsive checking was the fact that facilitated perseveration occurred when participants were asked to undertake the tasks in a negative mood using “as many as can” stop rules. Implications for the factors that develop and maintain compulsive checking are discussed

Some Remarks on Wittgenstein’s Philosophy of Mathematics

Drawing mainly from the Tractatus Logico-Philosophicus and his middle period writings, strategic issues and problems arising from Wittgenstein’s philosophy of mathematics are discussed. Topics have been so chosen as to assist mediation between the perspective of philosophers and that of mathematicians on their developing discipline. There is consideration of rules within arithmetic and geometry and Wittgenstein’s distinctive approach to number systems whether elementary or transfinite. Examples are presented to illuminate the relation between the meaning of an arithmetical generalisation or theorem and its proof. An attempt is made to meet directly some of Wittgenstein’s critical comments on the mathematical treatment of infinity and irrational numbers

The Theory of the Selfish Gene Applied to the Human Population

In a study drawing from both evolutionary biology and the social sciences, evidence and argument is assembled in support of the comprehensive application of selfish gene theory to the human population. With a focus on genes giving rise to characteristically-human cooperation (“cooperative genes”) involving language and theory of mind, one may situate a whole range of patterned behaviour—including celibacy and even slavery—otherwise seeming to present insuperable difficulties. Crucially, the behaviour which tends to propagate the cooperative genes may be “at cost” to the genes of some who may be party to the cooperation itself. Explanatory insights are provided by Trivers’ parent-offspring conflict theory, Lack’s principle, and Hamilton’s kin selection mechanism. A primary observation is that cooperation using language and theory of mind is itself interdependent with full human conceptualization of a world of objects and of themselves as embodied beings. Human capacities inhering in, or arising out of, the ability to cooperate are also responsible for a vitally important long-term process, the domestication of animals and plants. The approach illuminates the difference between animal and human sexual behaviour, and the emergence of kinship systems. Again, recent patterns of population growth become much more explicable. It is argued that the gene is the single controlling replicator; the notion of the meme as a second independent replicator is flawed

Exploring the Philosophy of Mathematics: Beyond Logicism and Platonism

A perspective in the philosophy of mathematics is developed from a consideration of the strengths and limitations of both logicism and platonism, with an early focus on Frege’s work. Importantly, although many set-theoretic structures may be developed each of which offers limited isomorphism with the system of natural numbers, no one of them may be identified with it. Furthermore, the timeless, ever present nature of mathematical concepts and results itself offers direct access, in the face of a platonist account which generates a supposed problem of access. Crucially too, pure mathematics has its own distinctive method of confirming or validating results - mathematical proof - which supplies a higher level of confidence and objectivity than that available elsewhere. The dichotomy of invention and discovery is too jejune a framework for analysing creative mathematical activity. The Gödelian platonist perspective is evaluated and queried through scrutiny of the part played by mathematical resources and constraints in relation to human activity. It appears that there can be non-causal mathematical explanations and mathematical constraint on purely natural processes. Valuable implications of Quine’s naturalism are explored, but one must be cautious of his thesis of confirmational holism. The distinction between algebraic and non-algebraic mathematical theories usefully contributes to our understanding of the internally differentiated nature of the subject

The Confusion of the Symbol and That Which Is Symbolised: Religion, the Nation State, Politics and Society

The extent of confusion between symbols and that which is symbolised is examined across five institutional spheres. Religion is the institution most marked by confusion of this type; indeed in some respects the symbolic message of religion may be the extent of the substantive reality. On the other hand, the very existence of the nation state may be judged to depend upon the exercise of the human imagination; hence providing a source of instability which may lead to the excesses of nationalism. In regard to social status, the main problematical element is a certain circularity: it is necessary to get people to exhibit differences in behaviour which are then used to justify or constitute the status differences themselves. In politics, the symbolism of left and right threatens to strangle creative thinking, while in education the tendency on all sides to orient towards public systems of measurement and grading undermines the claim that what is really important is pupil and student learning. A social cost is being paid for the failure to recognise and, where possible, address the issues identified