Inconsistencies in extensive games

In certain finite extensive games with perfect information, Cristina Bicchieri (1989) derives a logical contradiction from the assumptions that players are rational and that they have common knowledge of the theory of the game. She argues that this may account for play outside the Nash equilibrium. She also claims that no inconsistency arises if the players have the minimal beliefs necessary to perform backward induction. We here show that another contradiction can be derived even with minimal beliefs, so there is no paradox of common knowledge specifically. These inconsistencies do not make play outside Nash equilibrium plausible, but rather indicate that the epistemic specification must incorporate a system for belief revision. Whether rationality is common knowledge is not the issue.     

When love is not blind: rumination impairs implicit affect regulation in response to romantic relationship threat

The present research examined how rumination influences implicit affect regulation in response to romantic relationship threat. In three studies, the disposition to ruminate impaired the ability to maintain positive feelings about the romantic partner in the face of explicit or implicit reminders of relationship threatening events. In Study 1, a high disposition to ruminate was correlated with impaired down-regulation of negative feelings toward the partner in response to a hurtful relationship incident. Two follow-up studies manipulated relationship threat explicitly through an experiential recall procedure (Study 2) or implicitly through a subliminal evaluative-conditioning procedure (Study 3). In both studies only individuals with low disposition to ruminate were able to ward off negative feelings and maintain positive feelings toward the partner. These findings illuminate the role of implicit affect regulation in the context of relationship threat-and how it is inextricably connected with the processes underlying rumination.     

MORALITY AND NATURE: EVOLUTIONARY CHALLENGES TO CHRISTIAN ETHICS

Christian ethics accentuates in manifold ways the unique character of human nature. Personalists believe that the mind is never reducible to material and physical substance. The human person is presented as the supreme principle, based on arguments referring to free‐willed actions, the immateriality of both the divine spirit and the reflexive capacity, intersubjectivity and self‐consciousness. But since Darwin, evolutionary biology slowly instructs us that morality roots in dispositions that are programmed by evolution into our nature. Historically, Thomas Huxley, “Darwin's bulldog,” agreed with Darwin on almost everything, except for his gradualist position on moral behavior. Huxley's “saltationism” has recently been characterized by Frans de Waal as “a veneer theory of morality.” Does this mark the end of a period of presenting morality as only the fruit of socialization processes (nurture) and as having nothing in common with nature? Does it necessarily imply a corrosion of personalist views on the human being or do Christian ethics have to become familiar again with their ancient roots?     

Gratitude,Psychopathology and Subjective Well-Being: Results from a 7.5-Month Prospective General Population Study

Gratitude is considered an important source of human strength in achieving and maintaining good mental health. Although complete mental health encompasses the absence of psychopathology and the presence of subjective well-being, no studies to date have examined relations between gratitude and both mental health dimensions together. Moreover, most studies focused on specific samples with a restricted demographic range. Our study, therefore, examined (a) demographic variability in the grateful trait, and (b) prospective associations between gratitude and both dimensions of mental health: psychopathology and subjective well-being. Using a four wave prospective survey design in a large (N = 706) sample of Dutch adults (M age = 44, SD age = 14, Range = 18–80), we measured gratitude with the SGRAT, symptoms of psychopathology with the SCL-90, and subjective well-being with the PANAS and SWLS. Gratitude was significantly associated with age, gender, education level, and employment status. Multilevel time-lagged regression analyses showed that the grateful trait did not predict symptoms of psychopathology, but was a significant albeit weak predictor of subjective well-being, when adjusting for the effects of demographic factors, and prior levels of subjective well-being and psychopathology. Our findings indicate that the grateful trait is associated with demographic factors, and shows complex connections with the presence of well-being and absence of psychopathology. These dynamics should be taken into consideration when studying the role of gratitude in mental health, and developing, applying, and evaluating gratitude interventions with the aim of enhancing subjective well-being and/or reducing psychopathology.     

Image memorability across longer time intervals

You may find some images easier to remember than others. Recent studies of visual memory have found remarkable levels of consistency for this inter-item variability across observers, suggesting that memorability can be considered an intrinsic image property. The current study replicated and extended previous results, while adopting a more traditional visual long-term memory task with retention intervals of 20 min, one day, and one week, as opposed to the previously used repeat-detection task, which typically relied on short retention intervals (5 min). Our memorability rank scores show levels of consistency across observers in line with those reported in previous research. They correlate strongly with previous quantifications and appear stable over time. Furthermore, we show that the way consistency of memorability scores increases with the number of responses per image follows the Spearman–Brown formula. Interestingly, our results also seem to show an increase in consistency with an increase in retention interval. Supported by simulated data, this effect is attributed to a decrease of extraneous influences on recognition over time. Finally, we also provide evidence for a log-linear, rather than linear, decline of the raw memorability scores over time, with more memorable images declining less strongly.     

Blocking the Vagueness Block - A New Restricted Answer to the Special Composition Question

The vagueness objection seems to block any moderate answer to the Special Composition Question leaving us with the two extreme alternatives that there either is no composite object or that any set of things compose an object. In this technical paper I introduce the notion of causal objects and a definition of a predicate that permits the set of all parts to be divided into equivalence classes. On this view we can use equivalence classes of parts to define the notion of composite objects why vagueness is blocked. The block works in a hypothetical domain where all parts have a cause so the aim is not to suggest empirically detectable parts and composites, nor to claim any kind of existence of the things being defined, but to present a consistent account of a possible moderate answer to the Special Composition Question that avoids the vagueness objection. The underlying idea is that an object, as such, is not caused whereas its parts are. For example, if we have three caused parts A, B and C constituting the composite D, we have three things that are caused (A, B and C) whereas the composite D has no cause over and above the three causes of A, B and C.