Three approaches to the study of infant temperament

In temperament research, the sensitive quantification of individual differences is critical, and biases affecting temperament measures differ somewhat from those affecting normative studies of development. In this paper, we attempt to specify major biases and strengths of the three methods most widely used in the assessment of infant temperament: parent report, home observation, and laboratory observation. We also describe an ongoing research program in order to illustrate how potential biases may be negotiated. We conclude that choice of temperament measure or measures depends upon (a) the purpose of the assessment, (b) knowledge of empirical relations among methods, and (c) evaluations of the seriousness of potential measurement biases.     

White matter microstructure predicts individual differences in infant fear (But not anger and sadness)

We examine neural correlates of discrete expressions of negative emotionality in infants to determine whether the microstructure of white matter tracts at 1 month of age foreshadows the expression of specific negative emotions later in infancy. Infants (n = 103) underwent neuroimaging at 1-month, and mothers reported on infant fear, sadness, and anger at 6, 12, and 18 months using the Infant Behavior Questionnaire-Revised. Levels and developmental change in fear, sadness, and anger were estimated from mother reports. Relations between MRI and infant emotion indicated that 1-month white matter microstructure was differentially associated with level and change in infant fear, but not anger or sadness, in the left stria terminalis (p < 0.05, corrected), a tract that connects frontal and tempo-parietal regions and has been implicated in emerging psychopathology in adults. More relaxed constraints on significance (p < 0.10, corrected) revealed that fear was associated with lower white matter microstructure bilaterally in the inferior portion of the stria terminalis and regions within the sagittal stratum. Results suggest the neurobehavioral uniqueness of fear as early as 1 month of age in regions that are associated with potential longer-term outcomes. This work highlights the early neural precursors of fearfulness, adding to literature explaining the psychobiological accounts of affective development.

Highlights

• Expressions of infant fear and anger, but not sadness, increase from 6 to 18 months of age.
• Early neural architecture in the stria terminalis is related to higher initial levels and increasing fear in infancy.
• After accounting for fear, anger and sadness do not appear to be associated with differences in early white matter microstructure.
• This work identifies early neural precursors of fearfulness as early as 1-month of age.

     

THE READABILITY OF CONTENT TEXTBOOKS USED IN MIDDLE AND JUNIOR HIGH SCHOOLS

Current external criticism of American schooling includes an assumption that content textbooks used in upper grades fail to challenge the abilities of pupils. To investigate this assumption, the multiformula readabilities of 111 content textbooks currently employed in grades six through nine in 30 middle or junior high schools were obtained. Five and six formula, same sample readability data were collected and analyzed by 37 teacher researchers. Two or more formulas placed 49% of these texts one or more grade levels above grade of use. The results also were analyzed in light of current concerns about the accuracy and use of readability formulas. Readability placements varied notably and significantly between‐texts and within‐texts for each content area and grade level of use. Significant mean differences occurred in grade placement by formulas differing in comprehension criteria and in word count procedures. Extending sample selection from three to six and nine within‐text samples did not change readability estimates notably or significantly. Teacher researcher procedural error occurred rarely. Teacher participants preferred the formulas combining realistic school estimates with efficiency in estimation.     

The effects of environmental change on chicks' responses to a familiar stimulus

The purpose of the present experiments was to explore chicks' proximity seeking behaviour in relation to imprinting objects in unfamiliar settings. Experiment I showed that chicks, which were individually imprinted on a stationary imprinting object, displayed reduced proximity seeking behaviour when tested in a pen smaller than the rearing pen. This finding confirmed earlier work on the effects of changed pen size. Experiment II used continuous and intermittent noise rearing and testing conditions, in all possible combinations, and a stationary imprinting object. Increased proximity seeking was found in conditions where the auditory environment was changed from rearing to testing, a result apparently opposite to that obtained in earlier work. It is suggested that the effect of environmental change on proximity seeking may vary with the modality in which change occurs and the salience of the imprinting object.