Skip to main content

Yale-New Haven Hospital’s Monkeys

 


Are animals as stupid as human beings? Will they indulge in trading if trained? Will a dog exchange a bone with another dog for some favour like sex? Keith Chen, a professor of behavioural economics, wanted to know. So he conducted an experiment which came to be known as the Yale-New Haven Hospital’s monkey experiment. He was shocked by the results. And the hospital had to ask him to leave the monkeys alone.

Chen conducted his research on a group of monkeys. His choice was the capuchin, which is a cute, little, brown monkey with a small brain that is highly focused on food and sex. (Not very unlike many human beings, you are tempted to think.)

Chen, along with Venkat Lakshminarayanan, worked with seven capuchins at a lab set up by psychologist Laurie Santos at Yale-New Haven Hospital. The monkeys lived together in a large cage. At one end of the cage was a smaller cage which was the testing chamber, where one monkey at a time would enter to take part in experiments.

First, Chen and his colleagues taught the monkeys to use money. They gave them silver coins which they could use for buying food. Give the coin back to the researcher and the monkey gets the goodies. The monkeys learnt to buy the food of their choice by giving the coins to the particular researcher holding their choice food.

Then Chen experimented with price variation. How would the monkeys behave if he raised or lowered the prices of food items? To Chen’s surprise, the monkeys behaved quite like human beings. When the price of a particular food rose the monkeys bought less of it and when the price fell they bought more. The monkeys were rational enough.

What about their irrationality? To test that, Chen set up two gambling games. Coin toss was the gamble. Head or tail? A very common human gamble. The monkey was shown a grape first. Depending on the coin flip, the monkey would get that grape or a bonus one as well. In the second game, the capuchins were shown two grapes and if the coin flip went against him one grape would be taken away.

In the first game, a bonus is won. In the second, something is lost. Actually there is no difference in the final outcome. In the both the gambles, the final average number of grapes won by each monkey would be more or less the same. Yet we all have a natural aversion to loss and an equally natural preference for gain. What about the monkeys? Yes, they behaved just like us again. The monkeys abandoned the two-grape gamble and gathered around the one-grape researcher. The capuchins behaved as if the pain from losing a grape was greater than the pleasure from gaining one. That is quite irrational if you understand that there is no real gain or loss in the game. Yet ‘loss aversion’ is a strong economic behaviour of human beings. And of monkeys too!

Similar experiments were actually carried out with men before Chen came to the conclusion. He studied the behaviour of intra-day traders at stock markets and concluded that the data generated by the capuchin monkeys “make them statistically indistinguishable from most stock-market investors.”

The biggest surprise for Chen came soon enough. One morning the alpha male of the group did something unique. He scurried into the testing chamber as he had done many times, but on this day, instead of taking his 12 coins and going to buy food, he flung his coins into the main cage and ran after them. All the capuchins rushed to grab the coins. Each one, behaving just like normal humans, grabbed what he or she could. Chen and his colleagues were unsuccessful in their attempts to retrieve the coins from the monkeys. They had to give food in return for the coins the capuchins had grabbed illegally. The monkeys learnt that crime pays.

What shocked Chen, however, was not this. He watched one male capuchin going to a female with the coin he had grabbed. He offered the coin to her which she accepted and then immediately he had sex with her. What Chen originally construed as altruism was in fact “the first instance of monkey prostitution in the recorded history of science.” [The quote is from Super Freakonomics by Steven D Levitt & Stephen J Dubner which is the source of this entire post.]

As soon as the copulation was over, the female monkey which had received the illegal coin went to Chen to buy grapes with it.

The hospital to which the capuchins belonged called a halt to the experiments. They did not want to irreparably damage the social structure of the capuchins.

The social structures are artificial constructs and they inescapably affect our behaviour patterns. Just imagine, for the sake of momentary delight, a social system in which people supported one another with understanding and empathy. Wealth wouldn’t be a major value there. Greed wouldn’t be a dominating vice. Selfishness and jealousy would be suppressed since they would make you look like hideous gargoyles on a majestic edifice. Not practical, you would say. Why? Because we have already been thoroughly corrupted by our existing social constructs with their warped notions.

PS. This is powered by #BlogchatterA2Z

Previous post in this series: Xenophanes’s God

Tomorrow, the last: Zorba’s Secret

 

Comments

  1. A very interesting post discussing some very interesting experiments...

    ReplyDelete
  2. A very interesting experiment. Having a society with empathy and no wealth would as you say be unimaginable because yes we have been corrupted far too much.
    Deepika Sharma

    ReplyDelete
    Replies
    1. The social system alters people's behavior significantly. Memes, in Dawkins' sense, are as strong as genes.

      Delete
  3. The 'system' corrupts us morally and we let that happen. Nothing can be more sad than this. In the above experiment , the monkeys seem so intelligent but when we extrapolate the behavior to humans, have we really stopped evolving and lost sense of rationality ?

    ReplyDelete
    Replies
    1. We are evolving only at the intellectual level,probably. The heart belongs to the ape still.

      Delete
  4. This post was entertaining and disheartening in equal measure.

    The more I read about the experiment, the more human-like the capuchins behaved.

    Maybe we are all capuchins in a giant lab--like the dragonflies you mentioned in a comment on my blog once.

    ReplyDelete
    Replies
    1. I live with the hope (very faint and appearing like a delusion) that one day human beings will realise their folly and correct their systems.

      Delete
  5. It's true that we are manipulated by our societies, i remember my dad telling me " it would have been good if we didn't evolve." Your writing tells me why he had that different look on his face while saying it.

    ReplyDelete
    Replies
    1. The evolution gave us heaven in the next life at least 😅

      Delete

Post a Comment

Popular posts from this blog

The Adventures of Toto as a comic strip

  'The Adventures of Toto' is an amusing story by Ruskin Bond. It is prescribed as a lesson in CBSE's English course for class 9. Maggie asked her students to do a project on some of the lessons and Femi George's work is what I would like to present here. Femi converted the story into a beautiful comic strip. Her work will speak for itself and let me present it below.  Femi George Student of Carmel Public School, Vazhakulam, Kerala Similar post: The Little Girl

The Second Crucifixion

  ‘The Second Crucifixion’ is the title of the last chapter of Dominique Lapierre and Larry Collins’s magnum opus Freedom at Midnight . The sub-heading is: ‘New Delhi, 30 January 1948’. Seventy-three years ago, on that day, a great soul was shot dead by a man who was driven by the darkness of hatred. Gandhi has just completed his usual prayer session. He had recited a prayer from the Gita:                         For certain is death for the born                         and certain is birth for the dead;                         Therefore over the inevitable                         Thou shalt not grieve . At that time Narayan Apte and Vishnu Karkare were moving to Retiring Room Number 6 at the Old Delhi railway station. They walked like thieves not wishing to be noticed by anyone. The early morning’s winter fog of Delhi gave them the required wrap. They found Nathuram Godse already awake in the retiring room. The three of them sat together and finalised the plot against Gand

Cats and Love

No less a psychologist than Freud said that the “time spent with cats is never wasted.” I find time to spend with cats precisely for that reason. They are not easy to love, particularly if they are the country variety which are not quite tameable, and mine are those. What makes my love affair with my cats special is precisely their unwillingness to befriend me. They’d rather be in their own company. “In ancient time, cats were worshipped as gods; they have not forgotten this,” Terry Pratchett says. My cats haven’t, I’m sure. Pratchett knew what he was speaking about because he loved cats which appear frequently in his works. Pratchett’s cats love independence, very unlike dogs. Dogs come when you call them; cats take a message and get back to you as and when they please. I don’t have dogs. But my brother’s dogs visit us – Maggie and me – every evening. We give them something to eat and they love that. They spend time with us after eating. My cats just go away without even a look af

The Final Farewell

Book Review “ Death ends life, not a relationship ,” as Mitch Albom put it. That is why, we have so many rituals associated with death. Minakshi Dewan’s book, The Final Farewell [HarperCollins, 2023], is a well-researched book about those rituals. The book starts with an elaborate description of the Sikh rituals associated with death and cremation, before moving on to Islam, Zoroastrianism, Christianity, and finally Hinduism. After that, it’s all about the various traditions and related details of Hindu final rites. A few chapters are dedicated to the problems of widows in India, gender discrimination in the last rites, and the problem of unclaimed dead bodies. There is a chapter titled ‘Grieving Widows in Hindi Cinema’ too. Death and its rituals form an unusual theme for a book. Frankly, I don’t find the topic stimulating in any way. Obviously, I didn’t buy this book. It came to me as quite many other books do – for reasons of their own. I read the book finally, having shelv

Vultures and Religion

When vultures become extinct, why should a religion face a threat? “When the vultures died off, they stopped eating the bodies of Zoroastrians…” I was amused as I went on reading the book The Final Farewell by Minakshi Dewan. The book is about how the dead are dealt with by people of different religious persuasions. Dead people are quite useless, unless you love euphemism. Or, as they say, dead people tell no tales. In the end, we are all just stories made by people like the religious woman who wrote the epitaph for her atheist husband: “Here lies an atheist, all dressed up and no place to go.” Zoroastrianism is a religion which converts death into a sordid tale by throwing the corpses of its believers to vultures. Death makes one impure, according to that religion. Well, I always thought, and still do, that life makes one impure. I have the support of Lord Buddha on that. Life is dukkha , said the Enlightened. That is, suffering, dissatisfaction and unease. Death is liberation