Before we get to the Kool-Aid part, let's recap some horrible American history. Jim Jones was a complex man. Long story short, he was a communist and occasional Methodist minister who founded his own pseudo-church in the late 1950s, called the Peoples Temple Full Gospel Church - known in short as the Peoples Temple. (And yes, the omission of the possessive apostrophe is intentional, as the name apparently refers to peoples of the world.) While Jones called it a church, it was actually his version of a Marxist commune, with a smattering of Christian references thrown into his sermons/diatribes. The Peoples Temple was arguably a cult, demanding serious dedication (and financial support) from its members.
As the Peoples Temple grew throughout the 1960s, Jones lost the plot on the whole Marxism thing and began to preach about an impending nuclear apocalypse. He even specified a date (July 15, 1967), and suggested that after the apocalypse, a socialist paradise would exist on Earth. And where would that new Eden be? Jones selected the remote town of Redwood Valley, California, and moved the Peoples Temple there prior to the deadline.
As you know, that end-of-the-world deadline came and went with no nuclear holocaust. In the following years, Jones abandoned all pretenses of Christianity and revealed himself to be an atheist who had simply used religion as a tool to legitimize his views. Jones said: "Those who remained drugged with the opiate of religion had to be brought to enlightenment - socialism." Oh, and Jones was a drug addict, preferring literal opiates to metaphorical ones.
As media scrutiny increased and his political profile became more complicated, Jones became concerned that the Peoples Temple's tax-exempt religious status in the U.S. would eventually be revoked. He was also paranoid about the U.S. intelligence community. So in 1977, Jones again moved the Temple and its peoples, this time to a settlement he had been building since 1974 in the South American nation of Guyana. He named it "Jonestown," and it was not a nice place. It occupied nearly 4,000 acres, had poor soil and limited fresh water, was dramatically overcrowded, and Temple members were forced to work long hours. Jones figured his people could farm the land in this new utopia. It didn't hurt that he had amassed a multi-million-dollar fortune prior to arriving in Jonestown, though he did not share (or even use) the wealth. Jones himself lived in a small shared house with few luxuries.
U.S. Congressman Leo Ryan visited Jonestown in November of 1978, investigating allegations of human rights abuses within the Jonestown community. Ryan was accompanied by NBC News correspondent Don Harris, various other members of the media, and concerned family members of Jonestown residents. While visiting Jonestown, Congressman Ryan met a little over a dozen Temple members who wanted to leave (including a couple who passed a note reading in part, "Please help us get out of Jonestown" to news anchor Harris, mistaking him for Congressman Ryan). That number of defectors was actually quite low, considering the population of Jonestown, which was then over 900.
While processing paperwork to help Temple members return to the U.S., Ryan was attacked by knife-wielding Temple member Don Sly, but the would-be assassin was restrained before he could injure Ryan. Eventually the entire Ryan party plus the group of Jonestown defectors drove to a nearby airstrip and boarded planes, hoping to leave. But Jim Jones had sent armed Temple members (his creepily-named "Red Brigade") with the group, and the Red Brigade opened fire, killing Ryan, one Temple defector, and three members of the media - and injuring eleven others. Those who survived fled into the jungle.
When the murderers returned to Jonestown and reported their actions, Jones promptly started up what he called a "White Night" meeting, inviting all Temple members. But this wasn't the first White Night. On various occasions prior to the murders, Jones had hosted White Night meetings in which he suggested that U.S. intelligence agencies would soon attack Jonestown; he had even staged fake attackers around Jonestown to add an air of pseudo-realism to the proceedings (though it's hard to imagine that such a small community wouldn't recognize their own people pretending to threaten the Temple). Faced with this hypothetical invasion scenario, Jones offered Temple members these choices: stay and fight the imaginary invaders, head for the USSR, head for the Guyana jungle, or commit "revolutionary suicide" (in other words, mass suicide as an act of political protest). On previous occasions when Temple members mock-voted for suicide, Jones tested them: Temple members were given small cups of liquid purportedly containing poison, and were asked to drink it. They did. After a while, Jones revealed that the liquid didn't contain poison - but that one day it would. And, by the way, he had been stockpiling cyanide for years (not to mention piles of other drugs).
On the final White Night, Jones was not testing his Temple followers. He was killing them all.
After the airstrip murders outside Jonestown, Jim Jones ordered Temple members to create a fruity mix containing a cocktail of chemicals including cyanide, diazepam (aka Valium - an anti-anxiety medication), promethazine (aka Phenergan - a sedative), chloral hydrate (a sedative/hypnotic sometimes called "knockout drops"), and most interestingly... Flavor Aid - a grape-flavored beverage similar to Kool-Aid. We'll get back to that last one in a moment.
Jones urged Temple members to commit suicide in order to make a political point. Some discussion ensued - an alternate plan put forth by Temple member Christine Miller involved flying Temple members to the USSR - but Jones prevailed, after repeatedly telling his followers that Congressman Ryan was dead, and that would bring the authorities soon (an audiotape of this meeting exists, and is just as creepy as you'd think). Jones first insisted that mothers squirt poison into the mouths of their children using syringes. As their children died, the mothers were dosed as well, though they were allowed to drink from cups. Temple members wandered out onto the ground, where eventually just over 900 lay dead, including more than 300 children. Only a handful of survivors escaped Jonestown - primarily residents who happened to be away on errands or playing basketball when the mass suicide/massacre took place.
Jones, his wife, and various other members of the Temple left wills stating that their assets should go to the Communist Party of the USSR. Jones himself did not drink poison; he died from a gunshot to the head, though it's not entirely clear whether it was self-inflicted. (Because Jones likely died last or nearly so, he may have chosen suicide by gun rather than by cyanide, because a cyanide death is extremely traumatic - and he would have seen hundreds of people experiencing cyanide death's effects, including foaming at the mouth and convulsions.) Toxicology reports found high levels of barbiturates (sedatives) in his blood. Jones was reportedly hooked on a variety of substances, possibly explaining his increasingly erratic behavior over the decades.
In the wake of the tragedy at Jonestown, the phrase "drink the Kool-Aid" became a popular term for blind obedience, as the Temple members had apparently accepted cups of fruity poison willingly. What's strange is that, according to various accounts, the primary beverage used at Jonestown was actually Flavor Aid (sometimes styled "Flav-R-Aid") - although there is photographic evidence that packets of both Kool-Aid and Flavor Aid were present at the scene. In an early inquest (PDF), coroners referred to "Cool Aid" [sic] . But initial media coverage described the scene differently. One read, in part (emphasis added):
A pair of woman's eyeglasses, a towel, a pair of shorts, packets of unopened Flavor-Aid lie scattered about waiting for the final cleanup that may one day return Jonestown to the tidy, if overcrowded, little community it once was.
This snippet was from an article printed in the Washington Post on December 17, 1978, written by Charles A. Krause. Less than a month after the deaths, here was major media specifying that the beverage was "Flavor Aid," but "Kool-Aid" is the term that stuck in Americans' minds. Why?
The most likely explanation comes in three parts.
The Kool-Aid Brand
First, Kool-Aid was a better known brand than Flavor Aid. Flavor Aid was a Jel Sert product first sold in 1929 and it was a rival of Kool-Aid, which was introduced in 1927 in powdered form. (Trivia note: prior to the Kool-Aid powder, the same beverage was available in liquid form as "Fruit Smack." Powdering the drink reduced shipping costs.) So when Americans thought about a powdered fruity drink mix (at least one that was not "Tang"), "Kool-Aid" came to mind as the market leader. A major brand builder for Kool-Aid was Kool-Aid Man, the anthropomorphic pitcher of red Kool-Aid who is best known for his 1980s catchphrase "Oh Yeah!" He was already in the media spotlight in the 1970s.
The Merry Pranksters and LSD
Second, and more intriguing, was The Electric Kool-Aid Acid Test, Tom Wolfe's nonfiction book published in 1968. In the book, Wolfe follows Ken Kesey and the Merry Pranksters as they travel the country in their party bus, encouraging non-drug users to try LSD in an Acid Test - including a formulation of LSD in Kool-Aid, dubbed "Electric Kool-Aid." The book includes possibly the first negative instance of the phrase "drink the Kool-Aid," and it came a decade before the deaths at Jonestown. Wolfe's book includes this passage, describing a man who had a bad trip (emphasis added):
"... There was one man who became completely withdrawn ... I want to say catatonic, because we tried to bring him out of it, and could not make contact at all ... he was sort of a friend of mine, and I had some responsibility for getting him back to town ... he had a previous history of mental hospitals, lack of contact with reality, etc., and when I realized what had happened, I begged him not to drink the Kool-Aid, but he did ... and it was very bad."
Because of The Electric Kool-Aid Acid Test, many Americans were familiar with the idea of being urged to drink Kool-Aid containing, um, unusual chemicals - even if they hadn't themselves participated in an Acid Test. This familiarity perversely boosted the profile of Kool-Aid, especially in this particular (adulterated) circumstance.
Both beverages were there
Third, plenty of evidence suggests that both Kool-Aid and Flavor Aid were present at Jonestown - though there was more of the latter. Therefore, in a sense, everybody's right. It may simply come down to whether the term "Kool-Aid" is catchier than "Flavor Aid," and history decided - much to the consternation of Kool-Aid's marketing department.
Today, the phrase "drink the Kool-Aid" is firmly entrenched in popular language, although the evidence suggests that it should more realistically be either "drink the Flavor Aid/Kool Aid mix" or the even less-catchy suggestion by Al Tompkins of Poynter: "[drink the] grape-flavored drink mix laced with poison." I think this linguistic horse has left the barn, quenching our thirst for metaphors with it. "OH YEAH!"
For a thorough examination of the cultural and linguistic effects of the Jonestown massacre, check out "Drinking the Kool-Aid: The Cultural Transformation of a Tragedy" by Rebecca Moore. In it, she makes the point:
... References [to "drinking the Kool-Aid"] are not uniformly negative. On the contrary, they describe the positive qualities of corporate loyalty or team spirit. For example, when Michael Jordan, a former Chicago Bulls basketball player who now plays for a competing team, returned to his former home to attend a Chicago Bears football game, he was willing to drink "Bears' Kool-Aid." This meant that Jordan was willing to set aside basketball rivalries in support of the home team at a football game.
Moore's paper is just one part of the encyclopedic Jonestown Institute website.
It's also worth checking out this Chicago Tribune story rounding up various media mentions of Kool-Aid versus Flavor Aid, 30 years after the Jonestown massacre. If you're into documentaries, I recommend Jonestown: The Life and Death of Peoples Temple (it's on YouTube), which aired on PBS's American Experience in 2008.