Investigated the child's social ideas, namely notions about production means (factory, public transportation, farmland) and family influence on notion acquisition. 120 children of jive age groups (4 to 13 years) were clinically interviewed (sensu Piaget). Children's parents, workers and housewives of an Italian industrial centre, answered to questionnaires inquiring background information on parents and child and appraisal of child's level of understanding. Interview answers were classified on ten level sequences concerning father's job, home ownership, function and ownership of production means and produce. Correlational analyses and separate ANOVAs [5(age) × 2(sex) × 3(production mean)] in three subject areas (owner of production mean, of produce, and produce use) of interview answers reveal that children's ideas about different production means develop with differing rhythms through the same level sequences, which are clearly related to the general characterstics of intelligence described by Piaget. Questionnaires show that parents tend to furnish their children with the degree of information concerning jobs appropriate to the level of development at which the parents believe their children to be.