The responses of individuals and groups to urban life, to factory employment or to new technology are a product of the values, experiences and behaviour patterns that they have assimilated over time as members of particular communities and societies. Some groups and individuals are more open to change and more able to adapt to it than others. Decisions are taken to accept or resist an innovation on the basis of characteristics peculiar to the individual, household or group within the context of the local physical, social, economic, cultural and demographic environment.
Access to education may increase awareness of the health benefits of improved sanitation technology, while income will influence the ability of a household to acquire particular facilities. Personal experience and demonstration of alternative technologies may help to convince people that the benefits of the investment will outweigh any costs incurred. Community organizations and influential leaders can assist in marketing the concept by emphasizing factors valued locally. These may include the status attached to possessing a facility, or its functional value in terms of comfort. Equally, factors such as rapid increase in population which limits privacy may heighten the perceived need for innovations in sanitation.
People resist change for many reasons. There may be resentment towards outside "experts" who know little of local customs and who are perceived to benefit more from the innovation than local people. Leadership may not be united within a community. For example, those with traditional authority who fear a loss of power and status may oppose innovation strongly supported by political or educated elites. New technologies may be aesthetically unacceptable or conflict with established patterns of personal and social behaviour. Furthermore, households vary widely in the resources of money, labour and time available to them and have their own priorities. For those with limited resources, the costs in the short term of an apparently "low-cost" system may be too great when set against their need for food, shelter and clothing. In addition, in terms of capital investment latrines may be very costly for households if they take a long time to clean, are difficult to use or involve radical changes in social habits (Pacey, 1980). There may also be seasonal variations in the availability of money and labour. Thus the timing of the promotional aspects of a project in relation to, for example, agricultural seasons may be important in determining the local response.
The demographic composition, economic characteristics and attitudes to sanitation of individual households change over time. Experience shows that once people start to improve their houses their interest in latrines is likely to be aroused. Thus some households may be encouraged to install a latrine as one aspect of the modernization process. Projects should be flexible enough to allow households to invest in on-site sanitation not only when they feel motivated but also when they have the resources to do so. Indeed it may be most appropriate to introduce a range of on-site technologies within a particular community from which households can make a choice according to their own changing needs and priorities.