Howard Knox (1885-1949): a pioneer of neuropsychological testing

Posted in History on 23rd Oct 2014

Nov-14-full-issue-30Many visitors to New York will take the brief ferry trip from Battery Park to Liberty Island to see the Statue of Liberty (or “Liberty Enlightening the World” as Frédéric Auguste Bartholdi‘s monumental sculpture was originally called), and may then travel on to Ellis Island where many immigrants to the United States of America first arrived in the early 20th century.

Viewing the exhibits in the Ellis Island Immigration Museum, the visitor, particularly if from a neuroscience background, may be startled to come across early 20th century photographs of newly arrived immigrants being subjected to neuropsychological testing (Figure 1), and thus may encounter for the first time the work of the physician Howard Andrew Knox (1885-1949). This may prompt the curious visitor to seek more information on this little known and largely neglected figure in the history of neuropsychology, neglected that is until the work of John Richardson to which we are indebted for a vivid portrayal of the man, his work, and times.1,2

Knox worked as an assistant surgeon for the US Public Health Service at Ellis Island for just 4 years (May 1912-May1916). Then (as now) anxieties about immigration were prevalent, particularly the risk of large numbers of immigrants with “mental deficiency” being unable to work and hence becoming dependent on the public purse, along with the concerns of the eugenics movement that this would impoverish the racial stock of the country (mental deficiency was viewed at this time as a largely inherited trait). Ellis Island represented a front line for the identification of such immigrants, and their deportation back to their countries of origin (mostly in eastern and southern Europe). But how could such individuals be reliably identified among the mass of people arriving on a daily basis in the voluminous Ellis Island “hall of judgement”?

Along with colleagues at Ellis Island, Knox developed and popularized a number of tests which may be characterized as tests of performance, being one of the first to use this phrase to describe overt non-verbal behaviour. Tests existing at that time, such as the scale of Binet and Simon, assumed a particular culture and language that rendered them entirely unsuitable for use with the immigrants arriving at Ellis Island. It was recognized that new tests should as far as possible eliminate the language element and cultural knowledge, or in other words should be culture-free or, since this may not be possible, culture-fair. Richardson (ref 2, p 256) identifies Knox as the first proponent of such culture-fair tests.

Knox developed over a dozen tests over a short period of time, such as the Cube Imitation Test and the Feature Profile Test, as well as dabbling with ink blots (Inkblot Imagination Test) independently of Rohrschach, with whom they are more commonly associated. The purpose of the tests would be immediately familiar to any current neuropsychologist, for example the Cube Imitation Test is very similar to the visual working memory tests, such as that in the Wechsler Memory Scales 3rd Edition.3 Knox popularized his tests in over a dozen publications, including high profile journals such as the Journal of the American Medical Association4 and Scientific American.5 The latter article, now nearly a century old, represents one of the first attempts to explain a cognitive test battery to a broader scientific audience. Knox believed these constituted a graduated system of accurately standardized performance tests of increasing complexity suited to patient age, education and previous environment. Although none of Knox’s tests remains in use today, performance testing is still an integral part of neuropsychological assessment, as enshrined in the performance IQ component which was part of the Wechsler Adult Intelligence Scale up to the publication of the fourth edition of these scales in 2008.6

Figure 1: Knox (centre) apparently undertaking performance testing with a recently arrived immigrant at Ellis Island.

Figure 1: Knox (centre) apparently undertaking performance testing with a recently arrived immigrant at Ellis Island.

Besides the nature of the tests themselves, Knox was also alert to the issue of the test environment. Imagine that you have left your home, travelled thousands of miles by ship over a period of 10 days or so, perhaps in cramped and unsanitary conditions, with inadequate food and sleep, facing a future shrouded in uncertainty, and upon arrival at your destination you are then required to undertake some form of testing procedure which is entirely alien to the way of life and habits of thought which are familiar to you. Will your performance on such tests be optimal? Almost certainly not. Knox recognized the need for rest, adequate nutrition, sleep, a quiet and well-ventilated testing room, freedom from other distractions, as well as a sympathetic examiner and interpreter, for optimal test performance. He suggested that immigrants who failed initial testing should be given a second opportunity on subsequent days.5

Some of the issues which Knox tried to address remain with us today, specifically issues around language and culture, and test environment. Testing individuals in the cognitive clinic may be difficult if English is not their first language, hence the need for translation of many commonly used cognitive screening instruments, such as the Addenbrooke’s Cognitive Examination and its iterations7 and the Montreal Cognitive Assessment (see, into different languages. Knox understood the need not only to translate items but to develop different normative data for different cultural groups, something which is still lacking in many of our standard neuropsychological batteries a hundred years later. A number of cognitive screening instruments are claimed, sometimes on the basis of cultural modification and cross-cultural testing, to be culture-fair, such as the Clock Drawing Test, the Mini-Cog, the 7-minute screening battery, and the Time and Change test.8 It is now probably accepted by most neuropsychologists that whilst testing can be language free it cannot be culture free.

As for test environment, clinic rooms pervaded by extraneous noise (radio, television) and liable to interruption (passing outpatient department assistants, medical students) are still inappropriately assigned for cognitive clinics, sometimes for lack of more suitable accommodation. The problems which Knox faced 100 years ago are still likely to be with us in future years.


  1. Richardson JT. Howard Andrew Knox and the origins of performance testing on Ellis Island, 1912-1916. Hist Psychol 2003;6:143-170.
  2. Richardson JT. Howard Andrew Knox: pioneer of intelligence testing at Ellis Island. New York: Columbia University Press, 2011.
  3. Wechsler D. Wechsler Memory Scale – Third Edition (WMS–III). San Antonio, TX: The Psychological Corporation, 1997.
  4. Knox HA. A scale, based on the work at Ellis Island, for estimating mental defect. JAMA 1914;62:741-747.
  5. Knox HA. Measuring human intelligence. A progressive series of standardized tests used by the Public Health Service to protect our racial stock. Sci Am 1915;Jan 9:52-53,57-58.
  6. Wechsler D. Wechsler Adult Intelligence Scale – Fourth Edition (WAIS–IV). San Antonio, TX: Pearson, 2008.
  7. Davies RR, Larner AJ. Addenbrooke’s Cognitive Examination (ACE) and its Revision (ACE-R). In: Larner AJ (ed.). Cognitive screening instruments. A practical approach. London: Springer, 2013:61-77.
  8. Parker C, Philp I. Screening for cognitive impairment among older people in black and minority ethnic groups. Age Ageing 2004;33:447-452.

ACNR 2014;V14(5): 30-31.  Online First 21/10/2014


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