What happens if you give an elephant LSD? Researchers solved this mystery on August 3, 1962, when Warren Thomas, director of Lincoln Park Zoo in Oklahoma City, fired a cartridge-syringe containing 297 milligrams of LSD into the rump of Tusko the elephant. With Thomas were two colleagues from the University of Oklahoma School of Medicine, Louis Jolyon West and Chester M. Pierce. The dose was about 3000 times what a human would typically take. They later explained that the experiment was designed to find out if LSD would induce musth in an elephant - musth being a kind of temporary madness male elephants sometimes experience during which they become highly aggressive and secrete a sticky fluid from their temporal glands. One may also suspect a small element of ghoulish curiosity was involved.

Whatever the reason for the experiment, it almost immediately went awry. Tusko reacted as if he had been shot by a gun. He trumpeted around his pen for a few minutes then keeled over. Horrified, the researchers tried to revive him with a variety of antipsychotics, but about an hour later he was dead. In an article published four months later (Science, vol 138, p1100), the three scientists sheepishly concluded: "It appears that the elephant is highly sensitive to the effects of LSD." The experiment instantly made headlines. Faced with a public relations disaster, the scientists protested that they had not anticipated the elephant would die. In their experience, LSD was a powerful hallucinogen but rarely fatal. They helpfully noted that they themselves had previously taken the drug. Perhaps, mused one, the drug could be used to destroy herds in countries where they were a problem. For some reason, his suggestion has never found any takers. 2. TERROR IN THE SKIES

One day in the early 1960s, 10 soldiers boarded a plane at Fort Hunter Liggett military base in California on what they thought was a routine training mission. The plane climbed into the clear blue sky, levelled out at about 5000 feet and cruised for a few minutes before suddenly lurching to one side as a propeller failed. The pilot struggled with the controls and yelled frantically into his headset. Finally, he made an announcement over the intercom: "We have an emergency. An engine has stalled and the landing gear is not functioning. I'm going to attempt to ditch in the ocean. Please prepare yourself."

In such a situation, it would have been natural for the soldiers to feel fear or even terror. But there was no need. Though they didn't know it, they were in no danger. They were unwitting subjects in a study designed by the United States Army Leadership Human Research Unit near Monterey, California. Its purpose was to examine behavioural degradation under psychological stress - specifically, the stress of imminent death. Having created a fear-arousing situation, the researchers next introduced a task to measure the soldiers' performance under pressure - filling out insurance forms. A steward distributed the paperwork, explaining it as a bureaucratic necessity. If they were all going to die, the army wanted to make sure it was covered for the loss. Obediently, the soldiers leaned forward in their seats, pencils in hand, and set to work. They found the forms unexpectedly difficult to decipher, and quite likely they attributed this to the distraction of approaching death. In fact, the forms had deliberately been written in a confusing manner.

Eventually the last soldier completed his form, and they all steeled themselves for the crash. At that point the pilot turned the plane around - "Just kidding about that emergency, folks!" - and landed safely. Not surprisingly, anticipating a crash landing did interfere with the ability to accurately complete an insurance form. The soldiers made a significantly larger number of mistakes than did a control group on the ground who filled out the same paperwork (Psychological Monographs: General and Applied, vol 76, p1).

3. THE MASKED TICKLER In 1933 Clarence Leuba, a professor of psychology at Antioch College in Yellow Springs, Ohio, made his home the setting for an ambitious experiment. He planned to find out whether laughter is a learned response to being tickled or an innate one. To achieve this goal, he determined never to allow his newborn son to associate laughter with tickling. This meant that no one - in particular, his wife - was allowed to laugh in the presence of the child while tickling or being tickled. Leuba planned to observe whether his son eventually laughed when tickled, or grew up dismissing wiggling fingers in his armpits with a stony silence.

Somehow Leuba got his wife to co-operate, and so the Leuba household became a tickle-free zone, except during experimental sessions in which Leuba subjected R. L. Male, as he referred to his son in his research notes, to laughter-free tickling. During these sessions, Leuba followed a strict procedure. First he donned a cardboard mask, while also maintaining a "smileless, sober expression" behind it. Then he tickled his son in a predetermined pattern - first light, then vigorous - in order of armpits, ribs, chin, neck, knees, then feet.

Everything went well until April 23, 1933, when Leuba recorded that his wife had made a confession. On one occasion, after her son's bath, she had "jounced him up and down while laughing and saying, 'Bouncy, Bouncy'." It is not clear if this was enough to ruin the experiment. What is clear is that by month seven, R. L. Male was happily screaming with laughter when tickled. Undeterred, Leuba repeated the experiment after his daughter, E. L. Female, was born in February 1936. He obtained the same result. By the age of seven months, his daughter was laughing when tickled (Journal of Genetic Psychology, vol 58, p201). Leuba concluded that laughter must be an innate response to being tickled. However, one senses a hesitation in his conclusion, as if he felt that it all might have been different if only his wife had followed his rules more carefully.

4. THE LOOK OF EUGH Do emotions evoke characteristic facial expressions? Is there one expression everyone uses to convey shock, another for disgust, and so on? In 1924, Carney Landis, a graduate student in psychology at the University of Minnesota, designed an experiment to find out.

Landis brought subjects into his lab and drew lines on their faces with a burnt cork so that he could more easily see the movement of their muscles. He then exposed them to a variety of stimuli designed to provoke a strong emotional reaction. For instance, he made them smell ammonia, listen to jazz, look at pornographic pictures and put their hands into a bucket of frogs. As they reacted to each stimulus, he snapped pictures of their faces. The climax of the experiment arrived when Landis carried in a live white rat on a tray and asked them to decapitate it. Most people initially resisted. They questioned whether he was serious. Landis assured them he was. The subjects would then hesitantly pick the knife up and put it back down. Many of the men swore. Some of the women started to cry. Nevertheless, Landis urged them on. In the pictures Landis took, we see them hovering over the rat with their painted faces, knives in hand. Two-thirds of the subjects eventually did as they'd been told. Landis noted that most performed the task clumsily: "The effort and attempt to hurry usually resulted in a rather awkward and prolonged job of decapitation." Even when the subject refused, the rat did not get a reprieve. Landis simply picked up the knife and decapitated the rodent himself (Journal of Comparative Psychology, vol 4, p447). With hindsight, Landis' experiment presented a stunning display of the willingness of people to obey orders, no matter how unpalatable.

5. REVERSING DEATH Robert E. Cornish, a researcher at the Berkeley campus of the University of California during the 1930s, believed he had found a way to restore life to the dead - at least in cases where major organ damage was not involved. His technique involved seesawing corpses up and down to circulate the blood while injecting a mixture of adrenalin and anticoagulants. He tested his method on a series of fox terriers, all of whom he named Lazarus after the biblical character brought back to life by Jesus.

First Cornish asphyxiated the dogs and let them be dead for 10 minutes. Then he attempted to revive them. His first two trials failed, but numbers three and four were a success. With a whine and a feeble bark, the dogs stirred back to life. Though blind and severely brain damaged, they lived on for months as pets in his home, inspiring terror in other dogs. Cornish's research provoked such controversy that the University of California eventually ordered him off the campus. He continued his work in a tin shack attached to his house, despite complaints from neighbours that mystery fumes from his experiments were causing the paint on their homes to peel. 6. SLUMBER LEARNING

In the summer of 1942, Lawrence LeShan of The College of William & Mary in Williamsburg, Virginia, stood in the darkness of a cabin in an upstate New York camp where a row of young boys lay sleeping. He intoned a single phrase, over and over: "My fingernails taste terribly bitter. My fingernails taste terribly bitter. . ." - the professor was conducting a sleep-learning experiment. All the boys were chronic nail biters, and LeShan wanted to find out if nocturnal exposure to a negative suggestion could cure them. One month into the experiment, a nurse discreetly checked their nails during a routine medical examination. One boy seemed to have kicked the habit. Then, five weeks into the investigation, disaster struck. The phonograph broke. Faced with having to abandon the experiment, LeShan began standing in the darkness and delivering the suggestion himself. Surprisingly, direct delivery had greater effect. Within two weeks, seven more boys had healthy nails. By the end of the summer, LeShan found that 40 per cent of the boys had kicked the habit, and concluded that the sleep-learning effect seemed to be real (Journal of Abnormal and Social Psychology, vol 37, p406). Other researchers later disputed this, showing via brain-activity measurements that sleep-learning did not occur where subjects were fully asleep. (The American Journal of Psychology, vol 69, p76).

7. TURKEY TURN-ONS While researching the sexual behaviour of turkeys, Martin Schein and Edgar Hale of Pennsylvania State University discovered that male members of that species truly are not fussy. When placed in a room with a lifelike model of a female turkey, the birds mated with it as eagerly as they would the real thing. Intrigued by this observation, Schein and Hale embarked on a series of experiments to determine the minimum stimulus it takes to excite a male turkey. This involved removing parts from the turkey model one by one until the male bird eventually lost interest.

Tail, feet and wings - Schein and Hale removed them all, but still the clueless bird waddled up to the model, let out an amorous gobble, and tried to do his thing. Finally, only a head on a stick remained. The male turkey was still keen. In fact, it preferred a head on a stick to a headless body. The researchers speculated that the males' head fixation stemmed from the mechanics of turkey mating. When a male turkey mounts a female, he is so much larger than her that he covers her completely, except for her head. Therefore, they suggested, it is her head that serves as his focus of erotic attention.

Before we humans snicker at the sexual predelictions of turkeys, we should remember that our species stands at the summit of the bestial pyramid of the perverse. Humans will attempt to mate with almost anything. A case in point is Thomas Granger, the teenage boy who in 1642 became one of the first people to be executed in Puritan New England. His crime? He had sex with a turkey. 8. TWO-HEADED DOGS In 1954 Soviet surgeon Vladimir Demikhov shocked the world by unveiling a surgically created monstrosity - a two-headed dog. He created the creature in a lab at the Moscow Institute of Surgery by grafting the head, shoulders and front legs of a puppy onto the neck of a mature German shepherd.

Demikhov invited reporters from around the world to witness his creation. Journalists gasped as the two heads simultaneously lapped at bowls of milk, and then cringed as the milk from the puppy's head dribbled out the disconnected stump of its oesophageal tube. Of course, the puppy did not need to eat or drink; it received all its nourishment from the circulatory system of the older dog. But it liked to drink because its mouth became dry. It also enjoyed licking candy. Of particular interest was the extent to which the two heads shared a common set of sensory experiences. Reporters observed that when one head wanted to eat, so did the other. When it was hot, both panted. If one yawned, so did the other. Not all their emotions were identical, though. The older dog, annoyed at having the foreign head attached to his neck, occasionally tried to shake it off. This prompted the puppy to retaliate by biting his larger companion on the ear.

Demikhov's two-headed dog lived for only six days, but over the course of the next 15 years he constructed 19 more. None of these lived very long either - the record was a month - as they inevitably succumbed to tissue rejection. 9. THE VOMIT DRINKING DOCTOR How far would you go to prove your point? Stubbins Ffirth, a doctor-in-training living in Philadelphia during the early 19th century, went further than most. Way further.

Having observed that yellow fever ran riot during the summer, but disappeared over the winter, Ffirth hypothesised it was not a contagious disease. He reckoned it was caused by an excess of stimulants such as heat, food and noise. To prove his hunch, Ffirth set out to demonstrate that no matter how much he exposed himself to yellow fever, he wouldn't catch it. He started by making a small incision in his arm and pouring "fresh black vomit" obtained from a yellow-fever patient into the cut. He didn't get sick.

But he didn't stop there. His experiments grew progressively bolder. He made deeper incisions in his arms into which he poured black vomit. He dribbled the stuff in his eyes. He filled a room with heated "regurgitation vapours" - a vomit sauna - and remained there for two hours, breathing in the air. He experienced a "great pain in my head, some nausea, and perspired very freely", but was otherwise OK. Next Ffirth began ingesting the vomit. He fashioned some of the black matter into pills and swallowed them down. He mixed half an ounce of fresh vomit with water and drank it.

Finally, he gathered his courage and quaffed pure, undiluted black vomit fresh from a patient's mouth. Still he didn't get sick. Ffirth rounded out his experiment by liberally smearing himself with other yellow-fever tainted fluids: blood, saliva, perspiration and urine.

Healthy as ever, he declared his hypothesis proven in his 1804 thesis. He was wrong. Yellow fever, as we now know, is very contagious, but it requires direct transmission into the bloodstream, usually by a mosquito, to cause infection.

NEW SCIENTIST