Introduction A human understands people or objects through interaction. The more and longer they interact, the deeper the human understands the other. Long interaction can result in attachment and desire for further interactions. It may also result in boredom.
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.