Consumer behaviour is the study of individuals, groups, or organizations and all the activities associated with the purchase, use and disposal of goods and services, including the consumer's emotional, mental and behavioural responses that precede or follow these activities. Consumer behaviour emerged in the 1940s and 50s as a distinct sub-discipline in the marketing area. Consumer behaviour is an inter-disciplinary social science that blends elements from psychology, sociology, social anthropology, anthropology, ethnography, marketing and economics, especially behavioural economics. It examines how emotions, attitudes and preferences affect buying behaviour. Characteristics of individual consumers such as demographics, personality lifestyles and behavioural variables such as usage rates, usage occasion, loyalty, brand advocacy, willingness to provide referrals, in an attempt to understand people's wants and consumption are all investigated in formal studies of consumer behaviour. The study of consumer behaviour also investigates the influences, on the consumer, from groups such as family, friends, sports, reference groups, and society in general.