The Development of Anticipatory Smiling

When do infants begin to communicate positive affect about physical objects to their social partners? We examined developmental changes in the timing of smiles during episodes of initiating joint attention that involved an infant gazing between an object and a social partner. Twenty‐six typically developing infants were observed at 8, 10, and 12 months during the Early Social‐Communication Scales, a semistructured assessment for eliciting initiating joint attention and related behaviors. The proportion of infant smiling during initiating joint attention episodes did not change with age, but there was a change in the timing of the smiles. The likelihood of infants smiling at an object and then gazing at the experimenter while smiling (anticipatory smiling) increased between 8 and 10 months and remained stable between 10 and 12 months. The increase in the number of infants who smiled at an object and then made eye contact suggests a developing ability to communicate positive affect about an object.     

Loss functions for estimation of extrema with an application to disease mapping

It is often of interest to find the maximum or near maxima among a set of vector‐valued parameters in a statistical model; in the case of disease mapping, for example, these correspond to relative‐risk “hotspots” where public‐health intervention may be needed. The general problem is one of estimating nonlinear functions of the ensemble of relative risks, but biased estimates result if posterior means are simply substituted into these nonlinear functions. The authors obtain better estimates of extrema from a new, weighted ranks squared error loss function. The derivation of these Bayes estimators assumes a hidden‐Markov random‐field model for relative risks, and their behaviour is illustrated with real and simulated data.     

An Empirical Examination of Quality Certification in a "Lemons Market"

This article examines the effect third-party certification has on a market characterized by adverse selection. Using an original data set from the market for young thoroughbreds, we show that certification alleviates problems of adverse selection by examining the effect certification has on breeder decisions to retain or sell horses and the effect these decisions have on observed prices. Data on the racetrack performance of the horses confirm the results.     

Profile of Some Patients Who Prematurely Terminate Analysis

This paper is concerned with cases in which patients who have been well established in treatment decide to end it prematurely. In examining the issue among my patients who left against my advice, I isolated in some of them a number of common traits, of which the existence of a long-standing idealizing transference was central. Four of these cases are presented, including two in which the resistance was successfully penetrated and two in which it was not and the patient left treatment. The definition of premature termination is seen in the context of that of a complete analysis.     

The Effect of Learning Experiences and Context on Infant Imitation and Generalization

Over the first years of life, infants gradually develop the ability to retrieve their memories across cue and contextual changes. Whereas maturational factors drive some of these developments in memory ability, experiences occurring within the learning event may also impact infants' ability to retrieve memories in new situations. In 2 experiments we examined whether it was possible to facilitate 12‐month‐old infants' generalization of learning in the deferred imitation paradigm by varying experiences before or during the demonstration session, or during the retention interval. In Experiment 1, altering the length, timing, or variability of training had no impact on generalization; infants showed a low, but consistent level of memory retrieval. In Experiment 2, infants who experienced a unique context for encoding and retrieval exhibited generalization; infants who experienced the context prior to the demonstration session, or during the retention interval, did not. Specificity is a robust feature of infant memory and is not substantially altered by encoding experiences in an observational learning paradigm. Previous history with a learning environment can, however, impact the flexibility of memory retrieval.     

Optimal scaling of Metropolis algorithms: Heading toward general target distributions

The authors provide an overview of optimal scaling results for the Metropolis algorithm with Gaussian proposal distribution. They address in more depth the case of high‐dimensional target distributions formed of independent, but not identically distributed components. They attempt to give an intuitive explanation as to why the well‐known optimal acceptance rate of 0.234 is not always suitable. They show how to find the asymptotically optimal acceptance rate when needed, and they explain why it is sometimes necessary to turn to inhomogeneous proposal distributions. Their results are illustrated with a simple example.     

Construction and selection of quick switching double-sampling system: sample size tightening

A new sampling inspection system involving normal and tightened plans is presented. Performance measures are developed. The average sample number of the newly developed system is compared with those of existing plans. Procedures are indicated an tables are constructed for designing the system indexed by various combinations of parameters.     

Race and gender as bases of class fractions and their effects on earnings

Maints auteurs ont affirmé que la race et le sexe repreésentent des bases de fractions de classe en ce sens que leur construction sociale permet à des segments d'une classe de se constituer à partir de caractéristiques liées à la race et au sexe. Cependant, les études ernpiriques antérieures tendent à considérer seulernent la race et le sexe comme des facteurs de fractionnernent au sein de la classe ouvrière seulement. À l'aide des données du recensement de 1986, cette communication analyse lea effets interactifs de la race et du sexe sur le revenu considéré comme facteur de fractionnement des classes. Les recherches de l'auteur indiquent que les effets produits par le groupement par race et par sexe sont inégaux en ce qui trait au revenu, les hommes gagnant davantage que les femmes tout en étant davantage ‘fractionnés’ par le revenu que les femmes. Lorsqu'on fait abstraction des différences de revenu entre classes, la race et le sexe demeurent des facteurs explicatifs importants du niveau de revenu, bien que leurs effets soient plus marqués chez les cadres, les professionnels et les ouvriers. L'écart entre les sexes est plus prononcé, mais la race demeure importante comme facteur de fractionnement au niveau des revenus des homrnes, měme après correction pour tenir cornpte d'autres variables. L'auteur affirme que l'assimilation des relations de sexe et de race aux relations entre classes est insatisfaisante et qu'il existe de sérieuses considérations théoriques pour considérer que les causes des inégalités entre les sexes et les races se trouvent non seulement à l'intérieur du domaine de la production, mais également à l'extérieur de celui-ci. The literature has argued that race and gender are bases of class fractions in that their social construction enables segments of a class to be constituted on racialized and gender-linked characteristics. However, previous empirical works tend to consider race or gender as fractionalizing the working class only. Using the 1986 Census data, this paper analyses the interactive effects of race and gender on earnings as grounds of fractionalizing classes. The findings indicate that race and gender groupings produce unequal effects on earnings: males have an income advantage over females, but race fractionalizes the earnings of men to a greater extent than for women. When inter-class differences in earnings are removed, race and gender remain important in explaining earnings, although their effects are stronger among the managerial, the professsional, and the working class. The gender gap is more pronounced, but race remains important in fractionalizing the earnings of men even after controlling for other variables. The paper argues that it is insufficient to subsume gender and race relations under class relations, and that there are compelling theoretical grounds to consider gender and race inequality as having roots both within and outside the sphere of production.