An understanding of business customers and final consumers is crucial in marketing. This requires knowledge of why and how people buy. Major concepts and theories from the social and behavioural sciences provide a background to the study of why people buy. Behavioural topics include: perception, attitude and decision-making processes, and the psychology of purchasing. Social science topics include: values and lifestyles, mass communication and advertising, and buyer-seller relationships. This inter-disciplinary approach enables students to think about many different facets of customer/consumer behaviour.