As a young scientific researcher, Siegel had been confidently told by his supervisor that humans were the only species that seek out drugs to use for their own pleasure. But Siegel had seen cats lunging at catnip — which, he knew, contains chemicals that mimic the pheromones in a male tomcat’s pee —so, he wondered, could his supervisor really be right? Given the number of species in the world, aren’t there others who want to get high, or stoned, or drunk?
This question set him on a path that would take twenty-five years of his life, studying the drug-taking habits of animals from the mongooses of Hawaii to the elephants of South Africa to the grasshoppers of Soviet-occupied Czechoslovakia. It was such an implausible mission that in one marijuana field in Hawaii, he was taken hostage by the local drug dealers, because when he told them he was there to see what happened when mongooses ate marijuana, they thought it was the worst police cover story they had ever heard.
In many human cultures, the origin stories of plant-derived drugs involve tales of people observing and copying the habits of animals. In Ethiopia, for example, the discovery of coffee is attributed to goatherders who observerd their flock becoming frisky and high-spirited after consuming coffee beans. Goats are very fond of coffee, and modern plantations must be robustly fenced against them; their taste for the effects of caffeine may have prompted the plant, which spreads it seeds via animal droppings, to produce it. Theirs is a long-standing symbiosis, though human participation in the cycle is relatively new.
Both Johann Hari and Mike Jay also note another aspect of drug use in animals - that it is often closely related to their environment, and sometimes with trauma being suffered. Hari notes that in Vietnam, "the water buffalo have always shunned the local opium plants. They don’t like them. But when the American bombs started to fall all around them during the war, the buffalo left their normal grazing grounds, broke into the opium fields, and began to chew." In Professor Siegel's research, a mongoose avoided the hallucinogenic silver morning glory in its pen until its mate died in a storm. And Mike Jay cites the research of addiction psychologist Bruce Alexander, in which rats taken out of cages and given a pleasant environment to live in reduced their intake of a supplied morphine solution to 1/20th that of their caged neighbours.
In all, Jay concludes:
Such experiments do not disprove the claim that animals take drugs for their chemical rewards, but they do indicate that the impulse to take drugs is more than a simple behavioural reflex. In humans, of course, the variables become far more complicated. Sensory pleasure is an obvious component of most drug use, though the definitions of pleasure are as varied as human culture itself. But some drugs offer strictly functional benefits. The ability to alter consciousness in dramatic but controllable ways has many uses, and there is much evidence to suggest that humans have long used such drugs instrumentally: even, in some cases, elaborating their entire social systems around the heightened states of consciousness such substances produce.
Those of us who are old enough to remember the first half of the 'UFO era' have the definite perception that the public discussion of the topic has devolved. As a society, we are collectively stupider on this subject than we were a generation ago.