Le concezioni sull'origine delle specie in bambini di scuola primaria

Italian school children start studying evolution and the origin of species in elementary school during their history classes. Research into this topic is important from both a theoretical and a practical point of view: from a theoretical point of view naive biology is one of the liveliest areas of research in cognitive developmental psychology, while from a practical point of view it may provide suggestions for a school syllabus. The aim of the present study was twofold: firstly to examine children's thoughts before and after studying evolution at school; secondly to design a biology syllabus for second grade children which would lead to a better understanding of this topic (evolution?) in the third year. Research carried out among secondary school and university students (see Brumby,1984; Shultman, 2006) has revealed that creationist ideas and misconceptions about evolution are both widespread. Many students, for example, echoing Lamarck's theory, claimed that evolutionary changes are brought about by an organism's need or capacity for adaptation to changes in the environment. Darwin's theory appears to be difficult to grasp, but researchers disagree over the cause. Some relate this difficulty to environmental factors such as the spreading of creationist ideas, the little knowledge of genetics, the misleading way in which evolution and adaptation are presented in text books and popular science books. Others maintain that intrinsic factors, i.e. tendencies present in the human mind like essentialism, might also be responsible. The first aim of this study was to assess whether misconceptions in this field derive from misunderstandings regarding concepts which have been taught correctly or from concepts which have been taught implicitly or explicitly (Alter & Nelson, 2002) thus affecting further learning from a very early stage (Berti, 2002; Mason, 2006). In the latter(?) case it would be not only possible but desirable to start teaching the theory of evolution or some propaedeutic concepts in the first years of school. Research carried out among children in the United States (Samarapungavan e Wiers, 1997; Evans, 2000; 2001) shows that creationism is widespread among 7 to 8 year old children, while Lamarckian conceptions start emerging in 10 to 12 year old children. It would seem, then, that misconceptions develop very early. In order to identify Italian children's conceptions of the origin of species and to analyze in what way they are influenced by formal instruction two studies have been carried out. The first one compared second graders with third graders, while the second one studied third grade children before and after being taught "life on earth before man". Children's answers in both surveys fall into four main explanatory framework: a "creationist" framework ( animals were created by God and they have always stayed the same); a naturalistic’ framework (animals are a product of nature); an "evolutionist" framework (animals started as a natural process and have changed over time to their present form); a "mixed" framework (God created animals and at least some of them have undergone changes). Results show that when evolution is taught "creationist" answers decrease while "evolutionist" and "mixed" ones increase. When children are given no explanations of the mechanisms of evolution they tend to link the changes in animals to the passing of time. The second aim of this study was to understand whether it is possible to prevent misconceptions through early and correct teaching: two syllabuses have been designed; the second grade syllabus contains fundamental concepts for an understanding of topics related to the origins of species which are taught in third grade. Results show that children can acquire specific and complex knowledge even though at different levels of abstraction.