‘He's got his father's bias’: Parental influence on weight bias in young children

Our aim was to explore the role of parents in the transmission of stereotypical body size attitudes and awareness of weight loss strategies to preschool children. Participants were 279 3‐year‐old children and their parents, who provided data at baseline and 1 year later. Parents completed self‐report body size attitude and dieting measures. Child weight bias and awareness of weight loss strategies were assessed through interview. Over time, negative associations with large bodies and awareness of weight loss strategies increased. Fathers’ attitudes prospectively predicted boys’ weight bias and awareness of weight loss strategies. Among girls, parental attitudes were less predictive. Findings confirm the importance of fathers in the development of boys’ body attitudes and inform prevention programmes.     

A cost-benefit analysis of demand for food.

Laboratory studies of consumer demand theory require assumptions regarding the definition of price in the absence of a medium of exchange (money). In this study we test the proposition that the fundamental dimension of price is a cost-benefit ratio expressed as the effort expended per unit of food value consumed. Using rats as subjects, we tested the generality of this "unit price" concept by varying four dimensions of price: fixed-ratio schedule, number of food pellets per fixed-ratio completion, probability of reinforcement, and response lever weight or effort. Two levels of the last three factors were combined in a 2 x 2 x 2 design giving eight groups. Each group was studied under a series of six FR schedules. Using the nominal values of all factors to determine unit price, we found that grams of food consumed plotted as a function of unit price followed a single demand curve. Similarly, total work output (responses x effort) conformed to a single function when plotted in terms of unit price. These observations provided a template for interpreting the effects of biological factors, such as brain lesions or drugs, that might alter the cost-benefit ratio.     

A general structural equation model with dichotomous,ordered categorical,and continuous latent variable indicators

A structural equation model is proposed with a generalized measurement part, allowing for dichotomous and ordered categorical variables (indicators) in addition to continuous ones. A computationally feasible three-stage estimator is proposed for any combination of observed variable types. This approach provides large-sample chi-square tests of fit and standard errors of estimates for situations not previously covered. Two multiple-indicator modeling examples are given. One is a simultaneous analysis of two groups with a structural equation model underlying skewed Likert variables. The second is a longitudinal model with a structural model for multivariate probit regressions.This research was supported by Grant No. 81-IJ-CX-0015 from the National Institute of Justice, by Grant No. DA 01070 from the U.S. Public Health Service, and by Grant No. SES-8312583 from the National Science Foundation. I thank Julie Honig for drawing the figures. Requests for reprints should be sent to Bengt Muthén, Graduate School of Education, University of California, Los Angeles, California 90024.     

Interpreting canonical correlation analysis through biplots of structure correlations and weights

This paper extends the biplot technique to canonical correlation analysis and redundancy analysis. The plot of structure correlations is shown to the optimal for displaying the pairwise correlations between the variables of the one set and those of the second. The link between multivariate regression and canonical correlation analysis/redundancy analysis is exploited for producing an optimal biplot that displays a matrix of regression coefficients. This plot can be made from the canonical weights of the predictors and the structure correlations of the criterion variables. An example is used to show how the proposed biplots may be interpreted.     

Inattention-Hyperactivity and Reading Achievement in Children from Low-Income Families: A Longitudinal Model

This study examined how preschool inattention-hyperactivity is related to elementary school reading achievement. Prereading skills were hypothesized to be a link between them. This link was explored using longitudinal data on 105 low-socioeconomic-status (SES) children's inattentive-hyperactive behavior and prereading skills in Head Start and in kindergarten and their inattentive-hyperactive behavior and reading skills in first grade. A model of this relationship was tested using structural equation modeling. The results failed to show a significant path between inattention-hyperactivity and prereading skills at both the Head Start and kindergarten levels. A significant path was found between first grade inattention-hyperactivity and reading skills, confirming that the strong relationship between inattention-hyperactivity and poor reading achievement commonly found in children from other SES levels was also significant in this low-SES sample. Strong relationships were found between pre-reading skills and reading skills, as well as among hyperactivity levels at the three grades. The issue of the direction of the path of influence between attention-behavior and reading achievement is addressed briefly; however, the results indicate that further longitudinal work is necessary to resolve this issue.     

I'll Start My Diet Tomorrow: A Solution-Focused Approach to Weight Loss

This article illustrates through a personal case example how Solution-Focused Brief Therapy concepts can help people lose weight and keep it off.     

AN INDEX FOR ASSESSING WEIGHT CHANGE IN CHILDREN: WEIGHT/HEIGHT RATIOS1

Weight and height data from two studies were recomputed, and original data were computed using a Weight Index formula that accounts for the interaction of actual weight/height changes in growing children and compares this ratio with that of normed weight/height ratios for equal-aged children. Recomputing the data of one study showed that the Weight Index is a more sensitive procedure for assessing long-term behavioral treatment of obesity for girls than weight alone. Recomputing the data of a second study showed that the Weight Index formula is consistent for boys and girls and is a more sensitive procedure for assessing long-term effects of a variety of medical treatments for obesity than the Ponderal Index or weight alone. Computation of the data for 17 “normal” children in a preschool class showed a zero Weight Index score before and after a six-month interval elapsed without treatment. The procedure may be useful in assessing ponderosity or anorexia over intervals of six months or more with growing children or difference between actual and normed weight over shorter intervals.     

A comparison of the key-peck and treadle-press operants in the pigeon: differential-reinforcement-of-low-rate schedule of reinforcement

Key pecking and treadle pressing in pigeons were compared under concurrent (key-treadle) and single-operant differential-reinforcement-of-low-rate schedules of food reinforcement ranging from 5 to 60 sec (concurrent procedure) or 5 to 120 sec (single-operant procedure). Under both procedures, the two operants followed the same general law: decreasing response rate and reinforcement rate and increasing number of responses per reinforcement as a function of increasing schedule interval. High correlations were found between key pecking and treadle pressing for the measures of response rate, reinforcement rate, and responses per reinforcement. Regression equations allowed the prediction of treadle pressing from key pecking. More bursting occurred in responding to the key, and key pecking showed a more precise temporal discrimination than treadle pressing. A test for sequential dependencies between key and treadle responses showed significant dependencies not only under the concurrent procedure but also in data created artificially by merging key and treadle sequences from different pigeons under the concurrent procedure and from the same pigeon under the single-operant procedure. It seems likely that the sequential dependencies found were due to the independent action of the schedule on each operant and that behavioral dependencies did not occur with the concurrent training procedure. The key-peck operant does not appear to have any special qualities that preclude its use in discovering general laws of behavior, at least under the differential-reinforcement-of-low-rate schedule. The usefulness of the key peck in other situations requires direct experimental study.     

Stimulus control of differential-reinforcement-of-low-rate responding

Five pigeons were given single-stimulus training on an 8-sec differential-reinforcement-of-low-rate schedule followed by steady-state generalization training using 12 wavelength stimuli. Three birds had a high percentage of reinforced responses on the training schedule and flat generalization gradients of total responses. The birds with fewer reinforced responses had much steeper generalization gradients. Generalization gradients plotted as a function of both stimulus wavelength and interresponse time showed that for most birds, stimulus control was restricted to responses with long interresponse times. Responses with very short interresponse times were not under stimulus control and there was some evidence of inhibitory control of short interresponse times. Interresponse-times-per-opportunity functions, plotted as a function of stimulus wavelength, showed that stimulus wavelength controlled the temporal distribution of responses, rather than the overall rate of response. The data indicate that the differential-reinforcement-of-low-rate schedule generates several response categories that are controlled in different ways by wavelength and time-correlated stimuli, and that averaging responses regardless of interresponse-time length obscures this control.     

Stability of developmental status and risk of impairment at 24 and 36 months in late preterm infants

BackgroundFew studies investigated whether late preterm infants might have developmental delays in several domains in early life and how stable the lag in developmental status might be.AimWe aimed to examine the stability of potential delays across developmental domains at 24 and 36 months of age in late preterm (34°-36⁶ weeks) and term (≥37 weeks) children and whether the risk of delays remained high at 36 months.Study design, subjects, and outcome measureWe conducted a prospective cohort analysis of the children of pregnant women participating in the Vitamin Antenatal Asthma Reduction Trial (VDAART). 652 children who were prospectively followed up and had parent-completed Ages Stages Questionnaires (ASQ-3) questionnaires at both 24 and 36 months were analyzed to assess their domain-specific developmental status.Results6.61 % (42/635) of children had a late preterm birth. Developmental delays were stable between 24 and 36 months on all 5 domains for the children born preterm and on 4/5 domains for those born at term. The developmental domains with the status stability at 24 and 36 months in both late preterm and term children were the gross motor, communication, personal-social skills, and problem-solving. Late preterm children compared with term children remained at higher risk of delays at 36 months for gross motor, communication, and problem-solving skills (aOR = 4.54, 95 %CI: 1.81−10.79; aOR = 8.60, 95 %CI: 3.10−23.28 and aOR = 3.80, 95 %CI: 1.58−8.73, respectively).ConclusionLate preterm birth is associated with suboptimal development and stability in several domains at both 24 and 36 months and compared with term birth, requiring early monitoring and assessment of the developmental lag to avoid potential long-term implications.