Abstract
Results of an interview study with eighty-four secondary school students indicate that children's theories about inheritance may he well-developed and coherent (though many do not conform to accepted scientific theory) before the topic is taught in school biology. The research alerts teachers to a number of commonly held viewpoints—for example intra-specific variation is often explained in terms of developmental defects, many students believe that acquired characteristics are inherited, and many also appear not to understand the equality of parental gene contribution or the mechanism of inheritance generally. Although the results suggest some improvement in understanding with age, especially between 14 and 16 years, several alternative viewpoints persisted in the older age groups. The authors discuss the implications of the work for biology teachers and suggest that more emphasis be given in lower secondary courses to the significance of genetics to life in general and to man in particular. Links between existing knowledge of familiar instances of inheritance and more technical aspects of genetics will, it is proposed, be important in future learning.