The collected works of L.S. Vygotsky stated that academic or scientific concepts require a level of conscious awareness on the part of the child within everyday situations. Academic concepts can be any kind of concept, such as science concepts, mathematics concepts, language concepts and so on. Vygotsky theorised how these academic concepts could be developed by school aged children, but he said less about the prior to school period. Scientific concepts do not instantly develop in their final form but rather follow a process of conceptual development guided through adult–child interaction. It is understood that not any kind of social interactions can be considered developmental, but rather it is interaction which is purposeful and which is viewed as useful for a child’s development. Any kind of conceptual development requires the interaction with the ideal form as presented through adult interaction in social contexts. In any stage of development, ideal forms need to be present in the real context. Ideal in the sense that it acts as a model for that which should be achieved at the end of the developmental period; and in contrast, the real form represents the beginning point of child development (Vygotsky, in: Veer, Valsiner (eds) The Vygotsky reader, Blackwell Publishers, Oxford, pp 338–350, 1994). Many studies have documented the interactions between adults and children for developing scientific concepts in formal settings but little is understood about what happens in family homes for the prior to school age period. We do not know how scientific concepts develop during infants–toddlers everyday life at home. What kinds of social interactions in everyday family life support infants and toddlers to develop early forms of science concepts? This paper presents the findings of a study of infant and toddler learning of science at home. A total of around 30 h of video data were collected from three Bangladeshi families in Australia and Singapore. Three children aged from 10 to 36 months were filmed over 1 year in their everyday context. Informed by cultural-historical theory, the findings indicate that a form of conscious collaboration between parents and infants–toddlers is the key for developing small science concepts from rudimentary to final form. Small science has been defined as simple scientific narration of the everyday moments that infants and toddlers experience at home with their families. It was found that it was the families who filled the gap in understanding, through actively supporting the development of their infant–toddler’s higher mental function. Here the relations between infant–toddler real forms of development were carefully considered by the parents in relation to the ideal form that they created through collective dialogue of small science moments in the environment. If infants–toddlers learn these small concepts in their everyday settings, it is probable that they could link these early forms of understandings to learning abstract concepts later in school. This study contributes to understanding the nature of social interaction patterns for developing small science concepts in the everyday context of family life. This paper also provides pedagogical suggestions for early childhood science education.