1918 · US PUBLIC HEALTH SERVICE · ELLIS ISLAND · 6 SOURCES
"The critical point" was a glance.
Seven-tenths of all immigrants passed through Ellis Island. The manual called the first medical look at each one the critical point: once past it, an immigrant would never be seen again.4 Anyone singled out was held for mental tests.
This page quotes the manual's language about "defective" immigrants because it's part of the record. That framing was eugenic, and the manual was used to exclude and deport people.
From the line to the test room
STEP 1Primary inspectionA rapid look at everyone. Examining each person properly was impossible at the volumes involved, so officers tried to pick out those who might have a mental defect.4
STEP 2Held for examinationThose picked out were held for a more careful examination and, sometimes, prolonged observation.4
STEP 3Intensive examinationThe manual sets out the proper environment and attitude for this stage, with questions and foreign-language vocabularies for examiners.2
STEP 4CertificationImmigrants certified as not meeting mental standards could be deported under the restriction laws.3
Tests named in the manual:
Cube testHealy frameFeature profileShip testConstruction blocksCounting 20Days of the week
Knox's block-tapping task needed no shared language. The examiner tapped cubes in a sequence and the person copied it.5,6 Sequences get longer as you go.
Length 3
Press start and watch.
Our own sequences and stopping rule, played on screen. Knox used four wooden cubes on a table and a fifth to tap with. A memory-span task like this measures little about intelligence on its own, and Ellis Island examiners interpreted results through their own assumptions.
THE SCALE OF ITThousands of examinationsKnox reported tests on more than 4,000 suspected defectives in eighteen months, plus many more by his colleagues.6
THE MANA physician, not a psychologistHoward Knox worked on intelligence testing for just four years, from May 1912 to May 1916, as a Public Health Service officer on Ellis Island.5
THE POLITICSMedicine in the service of exclusionInstruction manuals openly called the "mentally defective" alien "an impossible burden which tends to perpetuate itself". Historians argue the inspection was misused to discriminate.3
References
[1]United States Public Health Service. (1918). Manual of the mental examination of aliens (Miscellaneous Publication No. 18). Washington: GPO. Internet Archive.archive.org
[2]Manual of the Mental Examination of Aliens, 1918 (contents and common terms). Google Books.books.google.com
[3]Howard A. Knox and intelligence testing on Ellis Island. Hektoen International (2023).hekint.org
[4]Manual of the Mental Examination of Aliens, US Public Health Service: Primary inspection (ID 1529). Eugenics Archive, Cold Spring Harbor Laboratory.eugenicsarchive.org
[5]Richardson, J. T. E. Howard Andrew Knox: pioneer of intelligence testing at Ellis Island. Columbia University Press (preview). Dokumen.pub.dokumen.pub
[6]Wikipedia contributors. Knox Cubes (accessed 1 Oct 2026).en.wikipedia.org
HOW TO CITE THIS PAGE
What's Your IQ. (2026). Manual of the Mental Examination of Aliens (1918). In Historical IQ Tests Archive. Retrieved October 1, 2026, from /en/historical-iq-tests/manual-mental-examination-aliens-1918
EDITORIAL RECORD
First published2026
Last reviewed1 October 2026
Sources6: the manual, archive and library records, and histories of Ellis Island testing
Open questionsPage count differs between catalogues (112 and 118 pages)