A preference for a thinner body shape is prevalent among females in Western culture and body dissatisfaction and dieting are reported in girls as young as nine years of age. Sociocultural pressure is considered a dominant impetus behind women's desire to conform to prescribed standards of appearance. The present study investigated the psychological processes operating in the development of body dissatisfaction in girls in their pre-adolescent and early adolescent years. Internalisation of the 'thin ideal' was hypothesised as a central component of this mechanism, following recent research with adult women highlighting relationships with body dissatisfaction and pathological eating. Three hundred and fifty six girls aged 9-12 years from independent, high-achieving schools completed questionnaires on awareness and internalisation of the 'thin ideal', body dissatisfaction, and specific psychological and interpersonal influences. The practice of dieting was assessed and the girls' body weight and height were measured. Body dissatisfaction and dieting were associated with greater Body Mass Index, although not restricted to overweight girls, and no difference was found between age groups. Internalisation of the thin ideal was found to mediate the relationship between awareness of the sociocultural standard of appearance and body dissatisfaction, and media exposure and the weight/eating-related attitudes and behaviour of the girls' mother and best friend independently predicted awareness. The predictive effects of maternal and peer weight/eating-related attitudes and behaviour remained when controlling for the other and for media exposure. Teasing frequency predicted body dissatisfaction when controlling for awareness and internalisation, suggesting that these operate as independent processes in body dissatisfaction development. Body dissatisfaction was further found to mediate the relationships between internalisation and dieting, and teasing and dieting. Self-esteem and teasing were not found to operate as moderators of the awareness-internalisation or internalisation-body dissatisfaction associations and possible explanations are explored. Identification of the psychological processes involved in the development of body dissatisfaction, which operate at a young age in some girls, highlights targets for intervention strategies to prevent girls becoming discontent with their body shape/size, engaging in dieting behaviour and possibly progressing to a clinical eating disorder
