Druggy Monkeys
Coming in at eighth in our top unethical psychology experiments is a tale of monkeys that climbed so high they never came down again. Which of the experiments do you think is worst?
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1969 |
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How addictive are drugs? |
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Tie monkeys up in a cage and allow them to inject themselves with addictive drugs. Leave them to it for up to sixteen months. |
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Monkeys given cocaine, codeine, amphetamines, alcohol or a cocaine-morphine mixture became addicted and in many cases overdosed and died. Morphine, mescaline and chlorpromazine, however, didn’t cause any addiction. |
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Getting primates to shoot up into oblivion isn’t generally thought of as particularly sporting behaviour. |
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2/5 |
More information
In the 1930s, research started in earnest in trying to understand why some drugs were addictive and how addictive they were. By the ‘60s, researchers were beginning to get pretty savvy at working out methods to study drug dependence. One of the methods they used was to teach animals such as rats and monkeys to inject themselves with a variety of narcotics. This point is where it starts to get a bit blurry in ethical terms.
Pioneering work at the University of Michigan used a piece of kit into which psychologists could pin a monkey’s arm. The monkey could reach a lever with its free arm and soon learned that pressing the lever meant an injection of drugs into their pinned arm.
The research was important in understanding the psychological and physiological effects of many drugs, but at a cost. Quite aside from the monkeys which tried so hard to escape that they broke their arms, the study results came at a cost.
Here are some of the highlights:
Morphine: “In no instance did any animal voluntarily discontinue self-administration of morphine. In a few instances, when injections were interrupted by catheter kinking, plugging or breaking, or by mechanical failure, the monkeys showed typical and severe abstinence syndromes during which they pressed the lever almost continuously in attempts to obtain morphine injections.”
Codeine: “The highest average daily dosage observed for one week was 600 mg/kg. This monkey died of convulsions during the succeeding week at a dosage level of 670 mg/kg on that particular day. All five monkeys died within 6 to 8 weeks of unrestricted intake of codeine.”
Cocaine: “The monkeys showed an extremely rapid loss of muscle mass and grand mal convulsions became frequent. Behaviour consistent with visual hallucinations (staring and grasping at the wall) and tactile hallucinations (continued scratching and biting of the skin of the extremities, to the point of producing extensive wounds and even amputation of the digits) was consistently observed. The monkeys also appeared to become unaware of their surroundings in that they ignored raisins and candy which were proffered by the experimenters.
Morphine-Cocaine: “Within a few days all four monkeys established a pattern of self-administration of both drugs, cocaine being the predominant choice during the day and morphine during the late evening and night … Although fewer convulsions developed than when cocaine was the only drug of self-administration, combined toxic effects of the two drugs consisted of delirium, marked motor impairment, anorexia and emaciation. The experiments terminated in death within 2 - 4 weeks.”
Amphetamines: “No grand real convulsions were observed nor did chewing of the forearms or digits occur. One monkey did pluck all of the hair off his arms and abdomen, however, indicating that mild tactile hallucinations may have been present.”
Alcohol: “During self-administration the monkeys showed severe motor incoordination and stupor, even to the point of light anaesthesia. During withdrawal, a characteristic abstinence syndrome with tremor, vomiting, hallucinatory behaviour and convulsions occurred as soon as 6 hours after the last dose.”
How about trying one of our other top tens:- Top Ten Geek Holidays
- Top Ten Stupid Science Studies
- Top Ten Work-related Ills
- Top Ten Killer Vegetables
- Top Ten Weird Drinks
- Top Ten Grim Parasites
- Top Ten Things Science Hasn't Explained
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