What Are the “True” Statistics of the Environment?

A widespread assumption in the contemporary discussion of probabilistic models of cognition, often attributed to the Bayesian program, is that inference is optimal when the observer's priors match the true priors in the world—the actual “statistics of the environment.” But in fact the idea of a “true” prior plays no role in traditional Bayesian philosophy, which regards probability as a quantification of belief, not an objective characteristic of the world. In this paper I discuss the significance of the traditional Bayesian epistemic view of probability and its mismatch with the more objectivist assumptions about probability that are widely held in contemporary cognitive science. I then introduce a novel mathematical framework, the observer lattice, that aims to clarify this issue while avoiding philosophically tendentious assumptions. The mathematical argument shows that even if we assume that “ground truth” probabilities actually do exist, there is no objective way to tell what they are. Different observers, conditioning on different information, will inevitably have different probability estimates, and there is no general procedure to determine which one is right. The argument sheds light on the use of probabilistic models in cognitive science, and in particular on what exactly it means for the mind to be “tuned” to its environment.     

Modeling Statistical Insensitivity: Sources of Suboptimal Behavior

Children acquiring languages with noun classes (grammatical gender) have ample statistical information available that characterizes the distribution of nouns into these classes, but their use of this information to classify novel nouns differs from the predictions made by an optimal Bayesian classifier. We use rational analysis to investigate the hypothesis that children are classifying nouns optimally with respect to a distribution that does not match the surface distribution of statistical features in their input. We propose three ways in which children's apparent statistical insensitivity might arise, and find that all three provide ways to account for the difference between children's behavior and the optimal classifier. A fourth model combines two of these proposals and finds that children's insensitivity is best modeled as a bias to ignore certain features during classification, rather than an inability to encode those features during learning. These results provide insight into children's developing knowledge of noun classes and highlight the complex ways in which statistical information from the input interacts with children's learning processes.     

Differential effects of mindful breathing, progressive muscle relaxation, and loving-kindness meditation on decentering and negative reactions to repetitive thoughts

Decentering has been proposed as a potential mechanism of mindfulness-based interventions but has received limited empirical examination to date in experimental studies comparing mindfulness meditation to active comparison conditions. In the present study, we compared the immediate effects of mindful breathing (MB) to two alternative stress-management techniques: progressive muscle relaxation (PMR) and loving-kindness meditation (LKM) to test whether decentering is unique to mindfulness meditation or common across approaches. Novice meditators (190 female undergraduates) were randomly assigned to complete one of three 15-min stress-management exercises (MB, PMR, or LKM) presented by audio recording. Immediately after the exercise, participants completed measures of decentering, frequency of repetitive thoughts during the exercise, and degree of negative reaction to thoughts. As predicted, participants in the MB condition reported greater decentering relative to the other two conditions. The association between frequency of repetitive thought and negative reactions to thoughts was relatively weaker in the MB condition than in the PMR and LKM conditions, in which these two variables were strongly and positively correlated. Consistent with the construct of decentering, the relative independence between these two variables in the MB condition suggests that mindful breathing may help to reduce reactivity to repetitive thoughts. Taken together, results help to provide further evidence of decentering as a potential mechanism that distinguishes mindfulness practice from other credible stress-management approaches.     

Perceived quality of maternal care in childhood and structure and function of mothers' brain

Animal studies indicate that early maternal care has long‐term effects on brain areas related to social attachment and parenting, whereas neglectful mothering is linked with heightened stress reactivity in the hippocampus across the lifespan. The present study explores the possibility, using magnetic resonance imaging, that perceived quality of maternal care in childhood is associated with brain structure and functional responses to salient infant stimuli among human mothers in the first postpartum month. Mothers who reported higher maternal care in childhood showed larger grey matter volumes in the superior and middle frontal gyri, orbital gyrus, superior temporal gyrus and fusiform gyrus. In response to infant cries, these mothers exhibited higher activations in the middle frontal gyrus, superior temporal gyrus and fusiform gyrus, whereas mothers reporting lower maternal care showed increased hippocampal activations. These findings suggest that maternal care in childhood may be associated with anatomy and functions in brain regions implicated in appropriate responsivity to infant stimuli in human mothers.     

Mimesis: Where play and narrative meet

There is a great deal of narrative in play and also of play in narrative, especially in the narrative and play of young children. Part of the reason for this may be that they share an important pattern or structure in the way they work as mental instruments, mimesis. Mimesis is a mode of representation in which the relation between the symbol that represents and the thing in the world that is represented is in some sense imitative; that is, the representation resembles the thing represented. The concept of mimesis is not precise, but it has two important, though not entirely distinct, strands which are based on two kinds of imitation: the imitation found in the indexical symbol, or sign, and the imitation that is found in literary representation. The general notion of imitation that these two strands share is somewhat elusive, but it seems clear that both play and narrative would share equally in it. Further consequences are discussed.     

Looking Good and Lying to Do It: Deception as an Impression Management Strategy in Job Interviews

The present study investigated job applicants' use of deception. The study examined applicants' deception on written applications, as well as in a job interview; whether individuals would lie to conform to job requirements; and whether extraversion and self-monitoring are related to lying. Fifty-nine candidates completed an application and interview. After the interview, candidates were informed that they were actually participating in an experiment. They then watched a videotape of their interview and indicated any lies they told. As hypothesized, it was found that applicants lied both on the job applications and during the interview, primarily to appear to conform to job requirements. Furthermore, candidate extraversion was positively correlated with number of lies told, although self-monitoring was unrelated to lying.     

Maternal sensitivity and behaviour problems in young children with developmental delay

Children with developmental delay are at increased risk for behaviour problems, but little is known about risk and resilience factors. Previous research has established links between maternal sensitivity and behaviour problems in typically developing children, but no studies have examined maternal sensitivity in the development of behaviour problems in children with developmental delay. In this study, we coded videotaped interactions of 30 2‐year‐olds with developmental delay and their mothers using the maternal behaviour Q‐sort and a child behaviour coding system. Mothers completed the child behaviour checklist when their children were 2 and 3 years old. Results revealed significant inverse relations between maternal sensitivity and concurrent and later externalizing problems, and significant positive relations between maternal sensitivity and concurrent observed appropriate behaviour (compliance and social engagement). This study informs developmental theory and identifies an important maternal variable that may reduce the risk of behaviour problems in children with developmental delay. Copyright © 2006 John Wiley & Sons, Ltd.     

Actual Utility, The Objection from Impracticality, and the Move to Expected Utility

Utilitarians are attracted to the idea that an act is morally right iff it leads to the best outcome. But critics have pointed out that in many cases we cannot determine which of our alternatives in fact would lead to the best outcome. So we can’t use the classic principle to determine what we should do. It’s not “practical”; it’s not “action-guiding”. Some take this to be a serious objection to utilitarianism, since they think a moral theory ought to be practical and action-guiding. In response, some utilitarians propose to modify utilitarianism by replacing talk of actual utility with talk of expected utility. Others propose to leave the original utilitarian principle in place, but to combine it with a decision procedure involving expected utility. What all these philosophers have in common is this: they move toward expected utility in order to defend utilitarianism against the impracticality objection. My aim in this paper is to cast doubt on this way of replying to the objection. My central claim is that if utilitarians are worried about the impracticality objection, they should not turn to expected utility utilitarianism. That theory does not provide the basis for a cogent reply to the objection. Originally presented at the 2004 Bellingham Summer Philosophy Conference, Bellingham Washington, August 2, 2004, with comments by Gustaf Arrhenius and Elizabeth Harman. I am grateful to Arrhenius and Harman for their challenging criticism, as well as to Chris Heathwood, Michael Zimmerman, Owen McLeod, Elinor Mason, Eric Moore and other participants at the Bellingham Conference for comments and suggestions. In October, 2004 I discovered Mark Strasser’s ‘Actual Versus Probable Utilitarianism’. I see that in that paper Strasser anticipates a number of the points I make here.