The notion of a purity test by which candidates are measured is similar to another political metaphor drawn from chemical analysis: the litmus test. But a purity test suggests an even more stringent scrutiny to weed out any ideological impurities.
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Historically, many subjects could be tested for purity—even language itself. In the preface to his landmark 1755 dictionary, Samuel Johnson wrote that he found “our speech copious without order, and energetic without rules,” while “adulterations were to be detected without a settled test of purity.” As a fixed phrase, purity test started showing up in the scientific literature a century later. One correspondent to Scientific American in 1864 expressed a desire for a “purity test of air” that would quantify the oxygen levels in “our densely crowded and often sickening public rooms.”
In the late 19th and early 20th centuries, chemical testing became more commonplace in agriculture and food preparation, with “purity tests” developed to ferret out contamination in everything from plant seeds and sugarcane to wine and beer. Purity tests also worked their way into advertising—most famously for Ivory soap, with its slogan, first rolled out by Procter & Gamble in 1882, pledging that each bar was “99 44⁄100 percent pure.”
One early political foray for the purity test occurred in 1912, when Kansas was deciding whether to adopt an amendment to the state constitution extending full suffrage to women. One Kansan woman wrote to The Hutchinson Daily Gazette to oppose the amendment, arguing that there were “better ways of purifying politics” than granting women the right to vote. If mothers trained their boys to be “pure, honest, upright and patriotic,” then when they become men, “their votes and the laws they will make will stand the purity test.”
Purity tests took a decidedly less puritanical turn a decade later, when the Jazz Age ushered in a loosening of conventional morals, personified by the fun-loving flapper. A 1922 “defense of the flapper” in The Daily Home News of New Brunswick, New Jersey, described the fad at women’s colleges known as the “purity test,” intended “to discover how many girls were given to flapper habits.” “Have you ever smoked, drank, petted?” constituted typical questions. “Girls who have ever taken one puff or one sip or who had held hands with the boy next door, were forced to say ‘Yes’ along with those who indulged habitually,” the writer explained.
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The following year, the Des Moines Register reproduced a “purity test” that was circulating among Iowa college students, with 10 questions running from “Have you ever been drunk?” and “Do you gamble?” to “Do you make a practice of promiscuous petting?” In Des Moines, at least, the test was administered by college girls as a way of sizing up the boys, and “purity” was far from a desired quality. As one “little bobbed-haired blonde” slangily divulged, “An awfully pure youth is the same as a dreadful oil can or a poor fish or a terrible dumbbell. Being ‘pure’ is a social error.”