The hundredth monkey

The story of the hundredth monkey is a good example of how pseudosciences arise and spread.

Colonies of Japanese macaques (Macaca fuscata) have been studied for years by ethologists. During the 1950s and 1960s, a colony of macaques on the island of Kōjima was carefully studied by a team of Japanese researchers. To make their research easier, the monkeys were fed by the researchers with sweet potatoes and other products, which were left for them on the island’s beach and other places. In 1953, a young monkey discovered that sweet potatoes left on the beach and encrusted with sand were tastier if they were washed in the sea before being eaten. The discovery spread slowly among the macaques in the colony, especially the younger. The oldest, however, did not learn this new behavior.

In 1965, the researcher Masao Kawai published an article recounting the results of 10 years of research with this population of macaques and says the following:

The acquisition of [this] behavior can be divided into two periods: before and after 1958... 1) The first period... of individual propagation... [in which the monkeys that acquired the new behavior did not learn it from their elders, but from individuals juveniles that had learned it before.] 2) The second period... of pre-cultural propagation [in which infant macaques learned it from their parents, as usually occurs in many animals.]

In 1979, Lyall Watson published a book (Lifetide) where he described what had happened on Kōjima as follows (the following is my summary and paraphrase of Watson’s statements):

In 1958, in the monkey population on the island of Kōjima, an unexpected phenomenon occurred. When a certain monkey (say the hundredth monkey) learned the new behavior (washing sweet potatoes in the sea) that behavior suddenly spread to the entire population. Not only that, but it also suddenly spread to other neighboring islands where it had not been detected before. This is so surprising that the Japanese team has not dared to publish all their results.

Watson draws from this the conclusion that the hundredth monkey phenomenon shows that when a certain number of beings learn a new behavior, that behavior passes spontaneously to the entire population, and even jumps outside its geographical limits, becoming racial knowledge. It should be noted that Watson is a supporter of extrasensory perception in man and uses this phenomenon of the hundredth monkey as support for his ideas in that field.

The phenomenon of the hundredth monkey spread like wildfire in environments related to the New Age, in which Watson moves. This phenomenon was used to claim that human beings could prevent a possible catastrophic nuclear war simply by increasing the number of people opposed to it. By crossing a threshold, surely that behavior would spread to the entire world population, and the danger would be averted.

Apparently, none of those who eagerly embraced the hundredth monkey theory and wanted to apply it to man bothered to check Watson’s documentation (five articles published by the Japanese team). In 1985, Ron Amundsen decided to investigate the matter by reading the literature. What he discovered was this (my paraphrase of his article):

The assertion that the Japanese team did not dare to publish all their discoveries is false. All the information is in the articles, especially that by Kawai mentioned above. It is false that in 1958 the conduct of washing sweet potatoes suddenly spread to the entire population. That year only two monkeys learned it. It is obvious that Watson misunderstood Kawai's words mentioned above, pointing out that 1958 marked a change in the mode of behavior transmission, because the infant macaques of the previous years became adults and began to teach it to their children. It is false that this behavior suddenly spread to neighboring islands. It is true that it appeared in some of them, but the cause could be its independent discovery, or the possible crossing of one of the monkeys who knew it from one island to another.

How did Watson answer criticism? He accepted that the hundredth monkey phenomenon was a figment of his imagination, and tried to justify himself by saying that he did not reference the Japanese articles as documentation, but as tools. As Amundsen points out, perhaps being refuted by your own tool is less painful than being refuted by your own documentation. Finally, although Watson admits that his phenomenon did not take place in Kōjima, he claims that it is true.

This is how many pseudosciences arise and spread: everyone accepts what their creators say, without bothering to confirm it. Perhaps soon we may see the emergence of new pseudosciences, whose creator will be ChatGPT and its successors (such as GPT4).

The same post in Spanish

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Manuel Alfonseca