What was Charles Manson’s IQ?
A line saying “later tested at 121” stood in Wikipedia’s article from May 2007 until November 2014, and no page we opened shows the test behind either number.
Charles Manson’s IQ is most often given as 109, from aptitude tests reported at the National Training School for Boys in Washington, D.C., in 1951; a second figure, 121, is described only as a later retest. No score sheet for either could be found, so this site’s estimated IQ is 100–120, an inference from the reported 109, not a measurement.
Charles Manson’s estimated IQ
- A reported IQ of 109 from aptitude tests given on his arrival at the National Training School for Boys in Washington, D.C., in 1951, when he was 16: Wikipedia states it and cites Jeff Guinn’s Manson (2013, p. 45) and Bugliosi and Gentry’s Helter Skelter (1974, pp. 136–146), and History Collection (September 1, 2019) repeats it with no source. We could not open either book.
- The same Wikipedia sentence says the tests found him illiterate. No page we opened names the test, the examiner or how it was given.
- A second number, 121, appeared in Wikipedia as a “later” test from at least May 2007 to November 2014, cited to Bugliosi; the wording was then changed to “later tested at age 21” and later dropped. No page gives its place, date or test.
- No score sheet, court exhibit or prison file with an IQ was found: the California Department of Corrections and Rehabilitation’s November 19, 2017 release on his death contains none, and the current Wikipedia article gives only the 109.
- There is no degree, rating or other academic record to cross-check. Wikipedia says that by his release on March 21, 1967 he had spent more than half of his thirty-two years in prisons and other institutions.
Both numbers are second-hand: a teenage test of unknown type, given to someone described as illiterate, and a retest with no place or date. Reading-heavy items could understate ability, and a 1951 test may not match modern norms. The range is an inference built around the reported 109, not a measured IQ.
- Born
- November 12, 1934, Cincinnati, Ohio (born Charles Milles Maddox)
- Died
- November 19, 2017, at a Kern County hospital, aged 83, in state custody (CDCR)
- Youth institutions
- Gibault School for Boys (1947), Indiana Boys School, National Training School for Boys (1951)
- Reported test
- Aptitude tests on arrival at the National Training School for Boys, 1951: IQ 109, illiterate; no score sheet seen
- Second number
- 121, “later tested” in Wikipedia’s text from at least May 2007 to November 2014; no test named
- 1971 record
- Seven counts of first-degree murder and one of conspiracy to commit murder (CDCR); a further first-degree murder conviction on December 13, 1971
- Sentence
- Death in 1971; modified to life on February 2, 1977 (CDCR)
- Measured IQ
- None on record
What an IQ of 100–120 actually means
Set the claim aside for a moment. If someone genuinely scored in this range, here is what that would represent.
Average is 100 by construction, and about two-thirds of people fall between 85 and 115. Take the test to place your own score on this scale.
| Score range | Classification | Share of people | What it indicates |
|---|---|---|---|
| 85 – 114 | Average | ~68% | The range most people fall into. |
| 115 – 129 | Above average | ~13.6% | Roughly one person in seven. |
| 130 – 144 | Gifted | ~2% | The threshold most high-IQ societies use. |
| Above 144 | Highly gifted | ~0.1% | Figures above this range are extrapolated from the curve rather than measured. |
Percentages are approximate and describe a normal distribution. The same number means different things on tests with different standard deviations.
Thirty questions gives you a measured position on this exact scale — your score, your percentile and the ability breakdown behind it.
Find out in 30 minutes →Who Charles Manson was
Charles Milles Maddox was born on November 12, 1934, in Cincinnati, Ohio (Wikipedia; Wikidata has the same date). This page covers only the IQ figures and the institutional record around them. Wikipedia says he was placed in the Gibault School for Boys in Terre Haute, Indiana, at 13 in 1947, and later sent to the Indiana Boys School near Plainfield. In 1951, after a federal stolen-car offense across state lines, he went to the National Training School for Boys in Washington, D.C., where the 109 is said to have been recorded.
In October 1951, on a psychiatrist’s recommendation, he was transferred to Natural Bridge Honor Camp in Virginia, according to Wikipedia. He later passed through the Federal Reformatory at Petersburg, Virginia, and a reformatory at Chillicothe, Ohio, and was released in May 1954. Later terms included Terminal Island, California, and McNeil Island, Washington, from July 1961. By his release on March 21, 1967, Wikipedia says, he had spent more than half of his thirty-two years in prisons and other institutions. No page we opened publishes a test result from any of them.
On January 25, 1971, a jury returned guilty verdicts against Manson and three co-defendants, according to Wikipedia, which cites Bugliosi and Gentry. The California Department of Corrections and Rehabilitation (CDCR) says he was admitted to state prison from Los Angeles County on April 22, 1971, for seven counts of first-degree murder and one count of conspiracy to commit murder, for deaths in August 1969. On December 13, 1971, he received a further first-degree murder conviction. He was originally sentenced to death.
The death sentence did not stand. Wikipedia says California’s death sentences were ruled unconstitutional after the 1972 decision in People v. Anderson. The CDCR release cites the same decision and says his sentence was modified to life on February 2, 1977; it adds that California did not have a life-without-parole sentence at the time. He died of natural causes at 8:13 p.m. on Sunday, November 19, 2017, at a Kern County hospital, aged 83, according to the same release. It says nothing about IQ or testing.
By Elora Mercer, Celebrity Research WriterFigures checked by Leon Falkner, Data & Research AnalystReviewed by Aarav Vardhan, Editor-in-Chief · Last reviewed October 2026
Charles Manson: the documented record
The estimate above rests on this record. Every entry here is a matter of public fact, which is more than can be said for the number itself.
- 1934Born November 12 in Cincinnati, Ohio, as Charles Milles Maddox.
- 1947Placed at the Gibault School for Boys in Terre Haute, Indiana, aged 13.
- 1951Sent to the National Training School for Boys in Washington, D.C.; aptitude tests on arrival are reported to give an IQ of 109 and to find him illiterate.
- 1967Released March 21, having spent more than half of his thirty-two years in prisons and other institutions.
- 1971Guilty verdicts on January 25; admitted to state prison on April 22 for seven counts of first-degree murder and one of conspiracy; a further murder conviction on December 13.
- 1972–77After People v. Anderson (1972) California’s death sentences are ruled unconstitutional (Wikipedia); his own sentence is modified to life on February 2, 1977 (CDCR).
- 2007A May Wikipedia revision says his IQ was 109, “later tested at 121,” citing Bugliosi.
- 2014On November 18 Wikipedia’s wording changes to “later tested at age 21”; the second test is gone by December 2018.
- 2017Dies November 19 at a Kern County hospital, aged 83.
- 2024EWASH (December 27) gives a range of 80 to 121 for his IQ, with no source.
Where the 109 figure came from
Following a claim back to its first appearance is the part almost nobody does — and it is what most people are actually asking.
Charles Manson’s IQ is usually given as 109, from tests said to have been given on his arrival at the National Training School for Boys in Washington, D.C., in 1951. Wikipedia says the aptitude tests found him illiterate, with an IQ of 109, and cites Jeff Guinn’s 2013 biography and Vincent Bugliosi and Curt Gentry’s Helter Skelter (1974). History Collection (September 1, 2019) puts his age at 16 and names no source. We could not open either book, so no test name or score sheet is available here.
Where does the Charles Manson IQ of 121 come from? The earliest page we found is an older version of Wikipedia. A May 2007 revision says his IQ was 109 and “later tested at 121,” citing Bugliosi, and versions through 2014 keep the line. In November 2014 the wording became “later tested at age 21,” and by December 2018 the second test was gone. EWASH (December 27, 2024) gives “a range of 80 to 121” with no source. No page we opened says where, when or by whom a retest was given.
On the usual scale (mean 100, standard deviation 15), a 109 is about the 73rd percentile and a 121 about the 92nd (our arithmetic). A Charles Manson IQ score of 109 sits near an IQ of 110, and 121 near an IQ of 120. Neither is easy to read. Wikipedia calls the 1951 tests aptitude tests and no page names the instrument (achievement tests versus IQ tests), and a test of that era may have used the old ratio formula (ratio versus deviation IQ).
Was Charles Manson a genius? Nothing documented says so, and this site’s estimated IQ of 100–120 is at the low end of the historical profiles. Frank Morris has a similar paper trail, a reported 133 first printed in a 1962 newspaper, though his range is 120–140. Ted Kaczynski’s page shows a dated score: a Full Scale 136 on the WAIS-R in 1996, recorded in a federal court document. Ted Bundy’s page also concerns a circulating number with no documented test, and this site traces celebrity IQ numbers the same way.
How we read a number →Died of natural causes at 8:13 p.m. on Sunday, November 19, 2017, at a Kern County hospital, aged 83; admitted to state prison from Los Angeles County on April 22, 1971, for seven counts of first-degree murder and one count of conspiracy to commit murder; first-degree murder conviction on December 13, 1971; originally sentenced to death; cites People v. Anderson (1972); “Manson’s death sentence was modified to life on February 2, 1977”; California had no life-without-parole sentence at the time. No IQ or intelligence test mentioned.
Label “Charles Manson,” description “American criminal and cult leader (1934–2017)”; date of birth 1934-11-12; date of death 2017-11-19: the entity is the person, not a namesake.
Born Charles Milles Maddox, November 12, 1934, Cincinnati; Gibault School for Boys (1947, cited to Guinn, p. 43); Indiana Boys School; National Training School for Boys, where “he was given aptitude tests which determined that he was illiterate, with an IQ of 109” (cited to Guinn 2013, p. 45, and Bugliosi and Gentry 1974, pp. 136–146); Natural Bridge Honor Camp, October 1951; McNeil Island from July 1961; released March 21, 1967 after more than half of his thirty-two years in institutions; guilty verdicts on January 25, 1971. No second test is mentioned. Neither cited book was opened.
2007: “a respectable 109 (later tested at 121)” cited to Bugliosi, p. 141; 2008 and 2012: “109 (later tested at 121)” cited to Bugliosi (the 2012 note gives pp. 137–146); 2010: “109 (later measured as 121)”; revision 634344938 still reads 121 and revision 634379867, a few hours later, reads “later tested at age 21”; 2018: “his IQ was 109 (the national average was 100)” with no second test.
“There, aged 16, he was given a psychological examination, revealing that, although his IQ was 109, he was illiterate.” Names no source for the examination.
Says most sources suggest “a range of 80 to 121,” with an average estimate of around 109, an early score of around 80, and later evaluations “reaching the 120-121 range.” Gives no source, test, date or place for any of them.
Reports an IQ of 109 from aptitude tests given in his youth and says he was illiterate; the only reference is a link to Wikipedia. No test, school or book named.
“He was illiterate, and his IQ was 109 (the national average was 100)”; no second test. A reference note points back to Wikipedia, so this is a copy, not an independent source.
No score sheet, court exhibit, prison file or institutional page stating an IQ was found in any page opened: the CDCR release and the current Wikipedia article give no second test. The books Wikipedia cites (Guinn, 2013; Bugliosi and Gentry, 1974) could not be read online, the Justia copy of People v. Manson (1976) returned HTTP 403, and a Crime Library page listed by search returned HTTP 404, so none of these is cited.
The sources behind our estimate
The figures that circulate for Charles Manson, what we were able to confirm, and where the two diverge.
109 is the figure that circulates for Charles Manson’s IQ score. Wikipedia says aptitude tests on his arrival at the National Training School for Boys found him illiterate, with an IQ of 109; History Collection (Tim Flight, September 1, 2019) says that at 16 an examination found his IQ was 109 though he was illiterate; La Cocina de Gisele repeats 109 and links to Wikipedia. A second number, 121, appears in older versions of Wikipedia (“later tested at 121,” May 2007 to November 2014) and, as the top of a stated range, on EWASH (Laura Young, December 27, 2024).
Every page that states a number points back to Wikipedia or names no source. Wikipedia cites Jeff Guinn’s 2013 biography and Bugliosi and Gentry’s Helter Skelter (1974) for the 109; we could not open either book, so we cannot say what they print or whether they quote a test report. History Collection names no source, and La Cocina de Gisele’s only reference is a link to Wikipedia. EWASH says most sources suggest “a range of 80 to 121” and gives no source. The California Department of Corrections and Rehabilitation’s 2017 release on his death has no IQ or test result.
The spread is 21 points, from the low end of this site’s range to 121. The 109 sits inside the range, near its middle; the 121 sits one point above the top. Neither comes with a test name, a date or a score sheet, and the 121 is described only as a later test, so the range stays wide.
Want a number that does hold up? Every figure on this page is somebody’s claim. Take the 30-question test and get a percentile you can check rather than a figure you have to trust.
Charles Manson — frequently asked
What is Charles Manson’s IQ?
Charles Manson’s IQ is most often quoted as 109, from aptitude tests reportedly given in 1951 at the National Training School for Boys in Washington, D.C., but no score sheet has been published. A second figure, 121, has no source. This site’s estimated IQ for him is 100–120, an inference from the reported 109, not a measurement.
Is Charles Manson’s IQ 121?
Not on any record we could open. The 121 appeared in older Wikipedia text as a “later” retest after the 109, citing Bugliosi’s book, from at least May 2007 to November 2014. The wording was then changed to “later tested at age 21,” and the current article gives only 109. No page names the test, date or place.
Did Charles Manson take an IQ test?
Reportedly yes. Wikipedia and History Collection say tests on his arrival at the National Training School for Boys in Washington, D.C., in 1951 found him illiterate with an IQ of 109. No page we opened names the test or shows a result, and Wikipedia calls them aptitude tests.
What was Charles Manson’s IQ score and level?
The reported 109 is about the 73rd percentile on a scale with a standard deviation of 15, and 121 is about the 92nd (our arithmetic). Neither is documented. This site’s estimated range of 100–120 runs from the 50th to roughly the 91st percentile and is an inference, not a measured score.
Where does the Charles Manson IQ of 109 come from?
Wikipedia cites Jeff Guinn’s 2013 biography Manson (page 45) and Bugliosi and Gentry’s Helter Skelter (1974, pages 136–146) for the 109. We could not open either book, so we cannot say what they print. The California corrections department’s 2017 release on his death contains no IQ.
Was Charles Manson a genius?
Nothing documented says so. The record has a reported 109 at age 16, a description of him as illiterate at that time, and no degree or later test result. Descriptions of his character in prison reports are judgments about behavior, not measurements of intelligence.
How does Charles Manson’s estimated IQ compare with Frank Morris’s?
Lower, and equally uncertain. This site’s range for Manson is 100–120, against 120–140 for Frank Morris. Both rest on a reported number with no test record: Morris’s 133 comes from a 1962 newspaper, Manson’s 109 from a Wikipedia sentence that cites two books we could not open.
How does my IQ compare with Charles Manson?
You can find out in about fifteen minutes. The IQ Metrics assessment is 30 questions, scored on the same 100-mean scale used throughout this page, so your result and the estimate above are at least expressed in the same units — one measured, one inferred. Once you have a number, the leaderboard shows where it would sit, and how we score and norm it explains the benchmarking.
Where does this estimate come from?
From the documented record rather than a test — the method is named above and set out in full under how we read a number. Compare it against the other historical profiles, starting with Isaac Newton.
- Take the 30-question IQ test — get a measured score and percentile of your own
- Average IQ by country — how the scale behaves across populations
- How IQ Metrics scores its assessment — the method behind our own number
- More on how IQ testing works — reliability, error and what a score can and cannot say
- More historical profiles — same field, same method
More historical
Booking photograph, U.S. Penitentiary, Alcatraz, 1960 (Commons file), public domain as a work of the U.S. federal government. · Portrait by Jacques-Louis David (1812), via Wikimedia Commons, public domain. · Portrait photograph of Adolf Hitler by Heinrich Hoffmann (1938; German Federal Archives, Bild 183-H1216-0500-002), retouched by Notwist; Commons file, CC BY-SA 3.0 DE. Cropped to the head and collar and with background removed for the portrait above.
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