100th Monkey Effect







Something started in 1952, which was accomplished by 1958, which had never been noticed before.

 The 100th Monkey Effect.

 The following is from 'Lifetide', by Lyall Watson. Book Club Associates, London, 1979. Pages 155-158.

The behaviour of the Japanese monkey Macaco fuscata has been studied intensely for more than thirty years in a number of wild colonies. One of these is isolated on the island of Koshimajust off the east coast of Kyushu, and it was here in 1952 that man provided the monkeys with the right sort of evolutionary nudge.

Provision stations were established at selected sites in the range of the troop. Normally young monkeys learn feeding habits from their mothers who teach them by example what to eat and how to deal with it, and in these macaques the behaviour had grown to a complex tradition involving the buds, fruits, leaves, shoots and bark of well over a hundred species of plants.

So they approached the new artificial food supplies equipped with a formidable array of behavioural predispositions, but nothing in their established repertoire enabled them to deal effectively with raw sweet potatoes covered with sand and grit.


Then an eighteen month old female, a sort of monkey genius called Imo, solved the problem by carrying the potatoes down to a stream and washing them before feeding. In monkey terms this is a cultural revolution comparable almost to the invention of the wheel. It involves abstraction, the identification of concept, and deliberate manipulation of several parameters in the environment.

And, reversing the normal trend, it was the juvenile Imo who taught the trick to her mother. She also taught it to her playmates and they in their turn spread the news to their mothers. Slowly, step by step, the new culture spread through the colony, with each new conversion taking place in full view of the observers who kept a constant watch right through all the daylight hours.

By 1958, all the juveniles were washing dirty food, but the only adults over five years old to do so were the ones who learned by direct imitation from their children.

Then something extraordinary took place.

The details up to this point in the study are clear, but one has to gather the rest of the story from personal anecdotes and bits of folklore amongst primate researchers, because most of them are still not quite sure what happened. And those who do suspect the truth are reluctant to publish it for fear of ridicule.

So I am forced to improvise the details, but as near as I can tell, this is what seems to have happened.  


In the autumn of that year an unspecified number of monkeys on Koshima were washing sweet potatoes in the sea, because Imo had made the further discovery that salt water not only cleaned the food but gave it an interesting new flavour.

Let us say, for argument's sake, that the number was ninety-nine and that at eleven o'clock on a Tuesday morning, one further convert was added to the fold in the usual way. But the addition of the 100th monkey apparently carried the number across some sort of threshold, pushing it through a kind of critical mass, because by that evening almost everyone in the colony was doing it.

Not only that, but the habit seems to have jumped natural barriers and to have appeared spontaneously, like glycerine crystals in sealed laboratory jars, in colonies on other islands and on the mainland in a troop at Takasakiyama.

The latest news from Japan is that Imo has by no means exhausted her powers, but has unleashed several additional cultural bombshells.

Another of the foods provided at the stations is wheat, which the monkeys enjoy but find difficult to deal with once it has blown out of containers onto the sand. Imo was only three when she solved this dilemma by picking up mixed handfuls of sand and wheat and winnowing the grain by casting both into the sea.

There the sand soon sank, leaving the wheat floating free on the surface where it could easily be scooped up and eaten. At the moment this subculture has spread only to Imo's immediate associates, but it will be fascinating to see what happens next.

I personally wouldn't be surprised if, in her later years, Imo re-invented agriculture. The relevance of this anecdote is that it suggests there may be mechanisms in evolution other than those governed by ordinary natural selection.

I feel that there is such a thing as the 100th Monkey Phenomenon and that it might account for the way in which many memes, ideas and fashions spread through our culture.

It may be that when enough of us hold something to be true, it becomes true for everyone.

Lawrence Blair says:  'When a myth is shared by large numbers of people, it becomes a reality.'

I'll happily add my one to the number sharing that notion, because it may be the only way we can ever hope to reach some sort of meaningful human consensus about the future, in the short time that now seems to be at our disposal. The war is between the old selfish instructions and the new self-awareness.

Where the two coincide, a truce is declared and progress takes place by leaps and bounds. But where they disagree, skirmishes are fought in the no man's land of the mind and ambivalent we, with all our special strengths and peculiar frailties, are the result.

Lyall Watson,  'LIFETIDE'. the 100th Monkey