The promotion of critical consumption in children is to be developed in primary school classrooms. Students will spend a total of 7 hours: (2 sessions of 1 hour per week) for 3 consecutive weeks, plus a feedback session (1 hour per week); and there will be another session with parents (1 hour per week). The psychologist tutor will receive a set of six activities related to discriminating between symbolic and critical yoghurt consumption in children, understanding the persuasive intent of yoghurt advertising, awareness of social pressure and critical attitude. Psychological tutors will be trained and provided with support materials and equipment.

As detailed in the description for the intervention group, the psychologist tutors guide the students in the classroom for two hours per week for three weeks in a row, plus a feedback session. There will also be a session with parents.

Five months after the start of the randomised clinical trial, primary school teachers in the control group will receive an unguided version of the psychoeducational intervention programme, supplemented by an online peer support group. They will be provided with the six activities related to critical consumption and awareness of the persuasive intent of advertising and social pressure for students to practice independently, in addition to online support from the research group. As in the intervention group, psychological support will be provided to children with emotional difficulties.

The promotion of critical consumption in children is to be developed in primary school classrooms. Students will spend a total of 7 hours: (2 sessions of 1 hour per week) for 3 consecutive weeks, plus a feedback session (1 hour per week); and there will be another session with parents (1 hour per week). The psychologist tutor will receive a set of six activities related to discriminating between symbolic and critical yoghurt consumption in children, understanding the persuasive intent of yoghurt advertising, awareness of social pressure and critical attitude. Psychological tutors will be trained and provided with support materials and equipment

The Symbolic Consumption Response Register (CRR) consists of 15 questions that are used to assess children's attitudes related to symbolic consumption. The frequency of children's symbolic consumption responses during the past week is rated on a 17-point scale (lowest frequency of symbolism = 1-4; intermediate frequency of symbolism = 5-13; highest frequency of symbolism = 14-17). Responses will be examined as an overall result and separately on understanding the persuasive intent of yoghurt advertising, on awareness of peer pressure and on critical attitude to consumption. Information for recording responses will be obtained from two interviews with the child and one interview with the parents, and from the six psychoeducational strategies developed with the children and one session with the parents. The answers of the children and their parents will be reported orally. The responses will be analysed separately.

The Symbolic Consumption Response Register (CRR) consists of 15 questions that are used to assess children's attitudes related to symbolic consumption. The frequency of children's symbolic consumption responses during the past week is rated on a 17-point scale (lowest frequency of symbolism = 1-4; intermediate frequency of symbolism = 5-13; highest frequency of symbolism = 14-17). Responses will be examined as an overall result and separately on understanding the persuasive intent of yoghurt advertising, on awareness of peer pressure and on critical attitude to consumption. Information for recording responses will be obtained from two interviews with the child and one interview with the parents, and from the six psychoeducational strategies developed with the children and one session with the parents. The answers of the children and their parents will be reported orally. The responses will be analysed separately.

Raven's Progressive Matrices Test-2 (RPM-2) is composed of 12 non-verbal colour items out of a total of 36, which allows the assessment of deductive ability independently of the knowledge acquired by children aged 9-12 years. The deductive ability at the time of assessment shall be determined on a 12-point scale (inadequate deductive level < 8 points; adequate deductive level = 8-12 points). The score achieved will be the expected result. The response record will be obtained from the child's non-verbal responses.

The facilitators of the psychoeducational program will use a form to record the events scheduled for each psychoeducational activity for both the children and their parents. The name, date, and duration of the activity will be documented. Records will be kept on each of the 5 participatory techniques, the story, the exhibition of 2 advertising videos on YouTube and the exhibition of 10 advertising posters. This information will be used to evaluate the quality of implementation of the interventions. To accomplish the full implementation of the psychoeducational programme, a total of 8 hours of intervention (2 sessions of 1 hour each per week) for 3 consecutive weeks and a 1 hour feedback session plus a 1 hour session with the parents are required. To stimulate a critical attitude towards symbolic consumption, a total of 8 psychoeducational activities should be carried out. In addition, the scores resolved in the 'B' series of the Raven's Progressive Matrices Test-2 (deductive capacity)