The

dynamics of mutual behavioural adaptation in the process of establishing social relationships in mouse lemurs (Microcebs murinus) and pygmy slow lorises (Nycticebus pygmaeus) was studied. Observations were made over a 3-hour period beginning when a male and a female were first placed together during the non breeding season. As well, the behaviour of stable pairs that had been together for more than one year was observed. Behaviour was recorded using the one/zero method with 5-sec intervals. Two stages of the development of social relationships, each with different functional values, were identified. The first stage involved mutual social investigation, the second the stabilization of the social relationship. Differences in the dynamics of social contacts between species members were due to their different social structures. The process of social adaptation of behaviour in dyads is discussed and quantitative and qualitative characteristics of breeding pairs and non breeding pairs are compared. It is suggested that a convenie nt strategy for improving breeding is to replace one of the partners with an experienced animal.