Body-size estimations in children six through fourteen: A longitudinal study

Estimates of perceived and ideal body size were collected in 216 boys and g irls ages 6 through 14 years. Video methodology was used to adjust the widt h of a life-size frontal image of the children. Longitudinal data were coll ected annually for three yeats, beginning at ages 6, 9, and 12. Three psych ological methods were used, including the method of adjustment, staircase m ethod, and adapt ive probit estimation technique which permitted separate m easures of the children's point of subjective equality and just noticeable difference values. The point of subjective equality is the body size which is subjectively equal to the child's perception of self. The just noticeabl e difference is the amount of change in body size necessary to detect the d ifference 50% of the time. Acceptable size boundaries were also measured, u sing the method of adjustment. Over-all, children were accurate in estimati ng their body width, with average overestimation of less than 2%. Overestim ation decreased within each age group during the three years of the study. There were no differences between ages or sexes. Both point of subjective e quality and just noticeable difference values decreased significantly durin g the three years of the study. The latter values significantly decreased a s children became older. Body dissatisfaction (the discrepancy between perc eived and ideal size) remained low for boys in all age groups. Girls' body dissatisfaction significantly increased across ages, beginning at age 9. Te st-retest consistency of both perceived and ideal size judgments at interva ls of one and two years were low. Acceptable boundaries in body width were similar between sexes and across age cohorts.