Interaction stimulates humans, and generates motivations for behaviors. There can be cases in which behaviors are not rational. Objects with which humans interact include natural objects, animals and artifacts. Studies on interaction between human beings and animals show positive effects on psychology, development of children, and so on. Such effects are subjective and could not be measured simply in terms of objective measures such as accuracy, energy and time.
Machines are also artifacts.
Different from the aesthetic objects, machines have been designed and developed as tools for human beings while being evaluated in terms of objective measures. Machines are passive basically because human beings give them goals. Machines will not be active as long as they are tools for human beings. However, if a machine were able to generate its motivation and behave voluntarily, it would have much influence to an interacting human. At the same time, the machine should not be a simple tool for humans nor be evaluated only in terms of objective measures.