One would expect that an Avatar coming to open a new evolutionary opportunity for consciousness in the world, would impact not only his own time and localized situation on the outer plane, but also be seen as establishing a new principle or capacity that tends to generalize itself across humanity thereafter. This impact may be seen in terms of an ethical, moral or socio-political effect on humanity as well as on the spiritual possibilities and powers of consciousness on the inner plane.
There is a phenomenon known as the “hundredth monkey” phenomenon that when a new skill is learned by a monkey, and then gets generalized to a larger group (the “hundredth” monkey), it becomes universally available to all monkeys even if they are not in the small group that actually initially gained the skill. It seems that the capacity generalizes itself at the level of consciousness once it has achieved a “critical mass”. Something similar can be seen when an Avatar brings forth a new level of consciousness and new principle of action. He acts directly on a relatively small group of people in his immediate surroundings, but once sufficient people begin to see and act from that level, we also can recognize a generalizing effect in the world at large.
Sri Aurobindo discusses the issues relating to the long-term impact of the Avatar: “The Avatar may descend as a great spiritual teacher and saviour, the Christ, the Buddha, but always his work leads, after he has finished his earthly manifestation, to a profound and powerful change not only in the ethical, but in the social and outward life and ideals of the race.”
“It is indeed curious to note that the permanent, vital, universal effect of Buddhism and Christianity has been the force of their ethical, social and practical ideals and their influence even on the men and the ages which have rejected their religious and spiritual beliefs, forms and disciplines…”
“Avatarhood is a fact of divine life and consciousness which may realise itself in an outward action, but must persist, when that action is over and has done its work, in a spiritual influence; or may realise itself in a spiritual influence and teaching, but must then have its permanent effect, even when the new religion or discipline is exhausted, in the thought, temperament and outward life of mankind.”
Sri Aurobindo, Essays on the Gita, First Series, Chapter 17, The Divine Birth and Divine Works, pp. 161-162