1986 clipping of the Guinness Book listing of Marilyn Mach vos Savant's IQ of 228 under the category of "Highest IQ", a title which she held until the 1989, after which the category was removed, on the basis that it is becoming incoherent to substantiate such a high IQ.
In IQs, Guinness Book IQs are those published in the Guinness Book of World Records under the section "Highest IQ", from at least the mid 1960s to circa 1990.

Category removal
The category was removed, in 1989/90 following an exaggerated test score sent into Guinness in 1983 that resulted to christen a previously unknown American writer Marilyn Savant as the world's smartest person, that was published for a period of about five years. The infamous sentence, pictured adjacent, found in the Guinness Book, from circa 1984 to 1989, reads:

“The highest childhood score has been achieved by Marilyn Mach vos Savant who as a 10-year-old achieved a ceiling score for 23-year-olds thus giving her an IQ of 228.”

The actual IQ she received on this test was 132. Nevertheless, Savant has passed into folk legend as the possessor of the highest IQ ever recorded, albeit under false pretenses. In sum, the category was removed on the grounds that it was impossible to justify this category; concluding that IQ tests are not reliable enough to designate a single world record holder. [10]

Early editions
The 1966 edition of the Guinness listed Christopher Harding (1945-) under the category, "The Smartest Man in the World"; in 1974, Harding founded the International Society for Philosophical Enquiry; about the third oldest high IQ society (IQ=146+).

A quote from the 1978 edition is: “HIGHEST IQ: This Korean boy, with a 210 quotient, at the age of 4 years 8 months spoke 4 languages ... A similar rating has also been attributed to Emanuel Swedenborg.” [2]

In the 1981 edition of Guinness Book, listed: “a figure of 210 has been attributed to Kim Ung-Yong”. [3]

The 1982 edition of Guinness, listed the ceiling of the Stanford Binet as IQ 200 and listed Kevin Langdon (IQ=196), of Berkeley, California, and Chris Harding (IQ=196), Bruce Whiting (IQ=196), of Boston, Robert Bryzman (IQ=196), Baltimore, and Leta Speyer (IQ=196) of New York city, as all having reported an IQ of 196 on the Stanford-Binet scale. [8] Kevin Langdon to detect intelligences beyond that which the MENSA tests were designed to do. He was starting a “Four-Sigma-Society”, for people, supposedly, like him who had four standard deviations above the mean, i.e. an IQ of 160 or above, one deviation being equal to 15 IQ points. [9]

In 1982, three people began to hold the title of world’s highest IQ of 197, Australian Christopher Harding, of Rockhampton, Queensland, and two Americans, a Dr. Johannes Veldunis, a university professor, and engineer Ferris Alger. [7]

On page seventeen of the 1985 Guinness Book, Christopher Harding is listed with a score of 197 on the Stanford-Binet scale. [4] The example article clipping is an example of a Guinness Book IQ citation, of Christopher Harding (IQ=197), as found in the June 25, 1991 issue of World Weekly News. [1] Harding was later intertwined with Savant, as discussed below.

The entire entry under "Highest IQ", on page 29, of the 1988 edition of Guinness Book of World Records, states:

"Intelligence quotients or IQ's comprise the subject's mental age divided by his chronological age or actual age multiplied by 100, so that an 8-year-old more gifted than an average 16-year-old would have an IQ of 16/8 × 100 = 200. The highest childhood score has been achieved by Marilyn Mach vos Savant of St. Louis, Mo, who as a 10-year-old achieved a ceiling score for 23-year-olds, thus giving her an IQ of 228.
In adult High IQ clubs, admission requirements are not on IQ points but are gauged in percentiles. An IQ exhibited by 1 person in 10,000 for instance coincides with 158 on the Stanford-Binet scale but 187 on the Cattell scale. The most elite ultra-high IQ society is the Mega Society with 26 members with percentiles of 99.9999 or 1 in a million. The topmost scorer in the Mega admission test, devised by its founder Ronald K. Hoeflin, has been 46 out of 48 by Marilyn Mach vos Savant superseding the 43 of Jeff Ward.
The 3 members who scored 197 are Christopher Philip Harding (b Keynsham, England, 1944) of Rockhampton, Australia; Dr Ferris Eugene Alger (b Des Moines, Ia, 1913) of New Hope, Pa, and Dr Johannes Dougles Veldhuis (b Hamilton, Ont, Canada, 1949) of Charlottesville, Va.
The highest IQ published for a national population is 115 for the Japanese born in 1960–61. At least 10 percent of their whole population has an IQ over 130."

 2009 psychology textbook excerpt of Savant defined as the person having the "highest IQ (230) ever officially recorded."

Marilyn vos Savant | IQ: 228?

The calculation of Marilyn Savant's now-famous IQ of 228 is a bit of a story, the details of it being described as a "bit murky", by New York Magazine reporter Julie Baumgold, as discussed in her 1989 article “In the Kingdom of the Brain”. [5] To begin with, Savant seems to have been an IQ test aficionado, taking them frequently in her childhood, joining Mensa in 1969 (age 23), and later becoming part of the "IQ test making industry", by consulting on IQ test manuals for Japanese students and later making IQ quizzes/puzzles as a job for Omni magazine.

● In 1953, age 7-years 7-months, Savant scored an IQ of 127 on a intelligence test, the ceiling of the test thus giving her an IQ of:

$IQ_{age 7} = 127 \,$

● In march 1957, age 11-years 4-months, according to actual records with the St. Louis board of education, she took the old version of the Stanford-Binet, geared for students aged 15 or younger, which according to IQ scale inventor Lewis Terman's age ratio IQ formula would give her an intelligence quotient of 132:

$IQ_{age11} = 100 \frac{15}{11+4/12} = 132 \,$

 Julie Baumgold's 1989 investigative article on Savant, explaining that in the calculation of Savant's enfamous 228 IQ the "derivation is murky". [5]

The story how this age eleven test score resulted fifty years later to her being listed as the "world's smartest person", as pictured (above) with a IQ of 230 is a bit convoluted, but boils down to number and date fudging.

As investigative reporter Julie Baumgold puts it in her 1989 article, shown adjacent, the "derivation is murky" and there is an entire "saga", which there seems to be, as discussed in detail below, to the 228 calculation.

 American lawyer Andrew Egendorf. American Mega Test creator Ronald Hoeflin. English Guinness Book editor Norris McWhirter.

● In short, twenty-six years later, during a 1983 dinner conversation American Lawyer Andrew Egendorf, the two concocted a publicity plan to convert her age 11 Stanford Binet score into the "world's highest IQ". During this period, Savant was a relatively unknown person, aside from having association in various up and coming IQ societies, and worked as an IQ puzzle writer for Omni magazine.

Egendorf was writing a book on high IQ societies and believed that if he got Savant the title of "Highest IQ" in Guinness Book, it would be a win-win situation for both of them. Egendorf sent her scores to Guinness on July 25 of that year.

● Savant then approached American Mega Society (1982) and Mega Test creator Ronald Hoeflin about sending supporting data into the Guinness Book. On this idea, Hoeflin comments:

“Marilyn told me she had received a perfect score on the Binet when she was ten. I computed it. I divided 22 years 11 months by 10 years 6 months, and her IQ was 218. Marilyn [also] showed me a report card that listed her IQ as 167+.”

The IQ of 167 figure, supposedly, comes from this calculation:

$100 \frac{17+10/12}{10+8/12} = 167 \,$

In other words, at age 10 years and 8 months (dates from Savant's memory), she aced a high school IQ test, or as one interview respondent put it: “When Marilyn was a ten-year-old student at Susan R. Buder school, she supposedly got a perfect score on the Stanford Binet. She hit the ceiling of that test, when appears on here school record as 167+. That figure was arrives at by dividing her mental age, recorded as 17-years 7-months [10-months, above calculation] by her chronological age, recorded as 10-years 8-months, and multiplying by 100”. As Hoeflin commented on this matter: “Guinness had been listing IQs of 196 as the world’s highest, but Hoeflin knew there were higher, as he states:

“Marilyn asked me to write on her behalf,” he says, and he did. Norris McWhirter, former editor of the Guinness book, says he based vos Savant’s listing on the material from the Mega Society. “I haven’t got anything original,” he says.

Thus the highest IQ in the world was born. “She values it as a way of getting publicity for her literary work,” says Hoefling. The problem here is that the date at which Marilyn told everyone she took the test were incorrect. As one reporter puts it:

“Both the month that Marilyn took the test and the mental age she achieved on it are matters of some question that contribute to the murkiness over the Guinness top score. Her record with the St. Louis board of education shows she took the test in March 1957; she insists she first took it in September 1956.”

“She says documents supporting her claims were provided by a teacher whose name she can’t remember and sent to Christopher Harding, a Mega society member, now in Australia.”

The second issue with her IQ calculation, is the jump from 167 to 228. To substantiate this, in her own words: “I answered some additional questions in the adult portion of the test to bring my score to a mental age of 22-years, 10-months.” This, however, would give her the following IQ:

$100 \frac{22+10/12}{10+8/12} = 214 \,$

This value seems to follow in alignment with this reporter finding: “She has an extremely high IQ, and scored a 167+ on the Stanford Binet when she was ten, but then the saga of the 228 gets a little complicated. Its derivation is murky, end even the man who helped present it to Guinness and compute the 228 now computes 218.” The reporter here, supposedly, is referring to Hoeflin. The value of 228 arose by the claim of Savant that she took her test at age ten, and assuming that the test ceiling mental age was 22 years and 10 months which yields a ratio IQ of 228:

$100 \frac{22+10/12}{10} = 228 \,$

The value of 230, such as depicted above in the 2009 psychology textbook, seems to have been arrived at by truncating all the dates to the simplified view that at age 10 Savant scored perfect on an age 23 intelligence test:

$100 \frac{23}{10} = 230 \,$

On a side note, Savant also took Marilyn vos Savant took Ronald Hoeflin's Mega Test in circa 1985 (age 39), scoring 46 out of 48, which, according to Hoeflin, corroborates to having an IQ of 186:

$IQ_{age 39} = 186 \,$

 American psychologist Alan Kaufman.
Savant IQ scam | Summary
In 2009, American noted IQ test psychologist Alan Kaufman summarized, in his book IQ Testing 101, that: [6]

“Miss Savant was given an old version of the Stanford-Binet (Terman & Merrill 1937), which did, indeed, use the antiquated formula of MA/CA × 100. But in the test manual's norms, the Binet does not permit IQs to rise above 170 at any age, child or adult. And the authors of the old Binet stated: 'Beyond fifteen the mental ages are entirely artificial and are to be thought of as simply numerical scores.' (Terman & Merrill 1937). . . . the psychologist who came up with an IQ of 228 committed an extrapolation of a misconception, thereby violating almost every rule imaginable concerning the meaning of IQs.”

In other words, according to American psychology professor Alan Kaufman, head of the Yale's University's Child Study Center, using the ceiling mental age of 15 of the test she took and the actual dates on record at the school she took the test, Savant's actual IQ based on this test would have been 132:

$100 \frac{15}{11+4/12} = 132 \,$

To correct this summary by Kaufman to note it was not a psychologist that came up with IQ of 228, but rather it was a combination of the figuring of Andrew Egendorf, Marilyn Savant, and Ronald Hoeflin.

Results
In sum, in 1983, Marilyn vos Savant cajoled her Mega Society members to unknowingly send in incorrect test dates, which don't match actual school records, to the Guinness Book to claim a 228 IQ (or 157 according to actual records), after which she become the reigning champion of the the world's smartest person category, for a period of about five years, or until 1989 or 1990. Whatever the publicity scheme worked:

(a) Within 3-years (1986), her "highest IQ" listing got her a job as a newspaper columnist for Parade Magazine, in the Sunday "Ask Marilyn" section;
(b) Within 4-years (1987), her "highest IQ" listing landed her a husband, American physician Robert Jarvik, inventor of the artificial heart, who sought her out after reading an article about her.

Iqbal Abba | IQ: 235?
According to a number of spurious Internet postings, dating from 2005, the removal of the "highest IQ" category story occurred because of Sri Lankan-born American “Iqbal Saleh Abba” (1962-), who in 1971, at the age of 5, according to his own account (2010) (Ѻ), “was doing partial non-linear differential equations, studying quantum mechanics, writting but never publishing articles in quantum electrodynamics, did work on the 3-body problem, and worked in philosophy, logic, epistemology, advanced mathematics, and science, and found errors in Laplace's celestial dynamics, and who at age 9, according to his own account (2014) (Ѻ), scored an IQ (ratio IQ) of 230 on the Stanford-Binet, a score that in 1989 he sent into the Guinness Book Records office, after which, supposedly, as a result of, in the 1990 edition, they removed the category of “highest IQ”. In 2012, Abba posted his opinion, supposedly, that he thinks that American philosoher Ronald Hoeflin’s mega test is “totally spurious test which does not measure anything except education level” (Ѻ).

This Abba person, to note, may not actually exist, akin to the 2006 fictional “William Alfred Quannigton” (Child IQ=350+; Adult IQ=300+) created as a joke in AnswerBag forum (Ѻ); being that no references to him, other than Internet postings, seem to exist.

References
1. Philips, Michael. (1991). “This Man Has World’s Highest IQ”, World Weekly News (pg. 38), June 25.
2. McWhirter, Norris. (1978). Guinness Book of World Records (category: Highest IQ, pg. 49). Bantam Books.
3. McWhirter, Norris. (1981). Guinness Book of World Records (pg. 35). Sterling Publishing Co.
4. (a) Broderick, Damien. (2009). Quipu: a Novel (Christopher P. Harding, IQ=197, pg. 1). E-rights.
(b) McWhirter, Norris. (1985). Guinness Book of World Records (pg. 17). Random House.
5. (a) Baumgold, Julie. (1989). “In the Kingdom of the Brain” How Love Changed the Smartest Couple in New York” (pg. 41). The New York Magazine. Feb 06.
(b) Listed in Guinness Book of World Records (for five years), circa 1990, under “highest IQ” for both child and adult scores.
(c) Knight, Sam. (2009). "Is a High IQ a Burden as Much as a Blessing?", FT.com, Apr 10.
6. Kaufman, Alan S. (2009). IQ Testing 101 (pg. 104). New York: Springer Publishing.
7. Anon. (1988). The Bulletin (pg. 42). Australian Consolidated Press.
8. McWhirter, Norris. (1982). Guinness Book of World Records (pg. 37). Bantam Books.
9. Erickson, Tim. (2006). The Fathom Guide for the Practice of Statistics (pg. 42). MacMillan.
10. Knight, Sam. (2009). “Is High IQ a Burden as Much as a Blessing?”, Financial Times, Apr 10.

Other editions
● Ross, McWhirter. (1975). Guinness Book of World Records (Highest IQ, pg. 50). Sterling Pub. Co.
● McWhirther, Norris. (1983). Guinness Book of World Records (Highest IQ, pg. 32). Bantam Books.
● McWhirter, Norris. (1986). Guinness Book of World Records (Highest IQ, pg. 16; Savant, pg. 16). Guiness Superlatives.
● Russell, Alan. (1987). Guinness Book of World Records (Highest IQ, pg. 23; Savant, pg. 23). Sterling Pub. Co. Inc.
● McFarlan, Donald. (1989). Guinness Book of World Records (Highest IQ, pg. 20; Savant, pg. 20). Sterling Pub Co.

Post 1990 editions
● Boehm, David A. (1990). Guinness Book of World Records (IQ, not found). Sterling.
● McMarlan, Donald. (1990). Guinness Book of World Records (IQ, not found). Bantam.
● McFarlan, Donald. (1991). The Guinness Book of Records (IQ, not found). Guinness.