Os limites das ações de comunicação que repousam sobre a informação e a persuasão são conhecidos. Se elas permitem modificar as atitudes e os saberes, elas não permitem, entretanto, modificar os comportamentos efetivos, porque boas atitudes não são suficientes para ter bons comportamentos. O objetivo deste artigo é propor uma nova abordagem de mudança social à luz da teoria do compromisso. Três estudos são relatados, mostrando sua eficácia para promover os comportamentos de cidadania desejados (participação eleitoral, proteção do meio-ambiente e economia de energia). Esta abordagem, chamada "comunicação do compromisso", apóia-se sobre os atos preparatórios e os atos de comprometimento que convém obter das pessoas enfocadas.

We already know the limits of communication actions based on information and persuasion. If that type of actions can lead to changing attitudes and knowledge, they hardly allow modifying the effective behaviours, simply because having the right attitudes is usually not enough to have the right behaviour. The goal of this article is to propose a new approach of social change in the light of the commitment theory. Three studies are reported, which show this theory efficiency to promote required citizenship behaviours: electoral participation, environmental protection and saving energy. This approach, called "committing communication", is based on preparatory acts and acts of commitment which are necessary to obtain from target subjects.

In ongoing studies on experimental transmission of Plasmodium falciparum in the city of Yaounde gametocyte carriers are daily being identified among dispensary patients with malaria-like complaints. This species comprises 93 of all parasitemias and because of the selection criteria most patients have it as a recent infection. 17 of all P. falciparum-positives carry detectable gametocytes with little difference between youngsters and adults. Blood of adult carriers is taken and infection of Anopheles gambiae mosquitoes is attempted by membrane feeding; the establishment of infection is judged by the presence of oocysts.