Unconscious Knowledge

Often we do not know that we know.

How often have you known how to do something yet haven't quite been able to say how and why? Most of us experience this at one point or another in our lives. Judging someone's facial expression for example. Most of us learn from a very early age what a sad or angry face looks like, yet even in adulthood few of us are able to verbally break down all of the individual components that make up these expressions. We simply...know. The same goes for a language that you've learned as a native speaker. Can you explain in detail why the linguistic structure that you use is the correct form? Unlikely, unless you happen to be a Professor of linguistics. The same goes for riding a bicycle, which while outwardly simple, requires a number of complex cognitive tasks and corresponding physical movements to ensure that you don't fall over.

Despite the inability of most people to fully express these activities verbally, to an outside observer watching you carry out all of these tasks, it becomes obvious that you do indeed have pre-existing knowledge in these areas. In some cases this knowledge might be correct and in others it might be wrong - quickly judging someone based on a stereotype for instance.1

These are all examples of what in psycho-cognitive terms is described as 'unconscious knowledge'.2 Research suggests that this form of knowledge that we acquire and store in an unconscious way, is more robust than knowledge that we acquire in explicit form.3 This is further supported by the fact that many unconscious kinds of knowledge are not lost in amnesia.4

This unconscious knowledge also points to an ancient and evolutionarily older form of cognition that evolved in our species. The Yorkshire born neurologist, John Hughlings Jackson, for instance, developed a theory which persists to this day - that when there is a loss of a mental function due to disease or natural deterioration, the higher and the more recently developed functions are lost first.5 A study by Swedish researchers in 2010 further found that these basic learning systems use areas of the brain that also exist in the most primitive vertebrates, such as certain fish, reptiles and amphibians.6

Though our ancient ancestors may have had their own thoughts on unconscious knowledge, it was not until until the 19th century that scientific psychology began a serious examination of this field. This was done via medical research of unconscious processes through hypnosis and sleepwalking.7 It was during this period that the word 'hypnosis' was coined by James Braid, a Scottish-born physician practising in Manchester.8 Dr. Braid named the phenomena after Hypnos, the Greek god of sleep.9

Interest in hypnosis and what the unconscious mind could potentially be capable of came to the fore with the fascinating trial in 1890 of Gabrielle Bompard, a Parisian woman who claimed to have committed murder while under the hypnotic influence of her lover. The case overflowed with riveting details worthy of any best-selling novel: a mysterious decomposing body in a trunk, seduction and lust, pioneering forensic work, international sleuthing, a fugitive in Havana, as well as false confessions and mutual accusations between Bompard and her lover.10

The trial sparked a volatile medical debate over the potential susceptibility of the average person to hypnotic influence and the consequent breakdown of moral restraints.11 The case was covered extensively in French and foreign presses, and though Bompard ultimately escaped capital punishment, it drew so much public attention that some 20,000 spectators eventually visited the Paris morgue to see the trunk in which Bompard's body had been disposed.12

Decades later, led by state funding and Cold War paranoia, research into unconscious knowledge took on a more militaristic and national security direction during the 20th century.13 Here, perhaps the most controversial example of unconscious knowledge came during the 1950s when the term brainwashing was coined to explain a strange series of events that took place in North Korea. During the Korean War, the North Korean Army had captured a number of U.S. soldiers and subjected them to physical and psychological torture. The surprise came afterwards though, when it was rumored that some of the U.S. soldiers had inexplicably renounced their values and had become loyal supporters of Communism. These events seemed to defy rational explanation. Edward Hunter, a reporter working for a Miami newspaper, wrote at the time:

Unrevealed tens of thousands of men, women and children had their brains washed in Red China.... [brainwashing causes] actual damage... to a man's mind through drugs, hypnotism, or other means, so that a memory of what had actually happened would be wiped out of his mind and a new memory of what never happened inserted.14

As would later be revealed though, the behaviour of the US soldiers had less to do with any mind-bending drugs or innovative scientific techniques and more to do with the effects of persuasion to cooperate.15 Nevertheless, these stories had captured people's imagination and became further ingrained in popular culture with the release in 1959 of 'The Manchurian Candidate' - a book (and later more famous film adaptation) revolving around an infantry platoon kidnapped and 'brainwashed' during the Korean War.

Moving forwards to the last several decades, a number of studies have indicated that unconscious knowledge is also qualitatively different from conscious knowledge and acquired by means or cognitive pathways distinct from those that produce conscious knowledge.16 Taking our definition of unconscious knowledge one step further, not only can you be unaware of how you know, but the recalling of that knowledge can also take place completely outside of consciousness. Put simply, information that you might have learned and stored, is recalled in an unconscious way - certain athletic motions refined over many hours of training for example, or knowing how to respond to a specific customer query without having to consciously think it through. This is what we often mean when we mention experience and the ability to immediately discern the right solution to different scenarios.

While this type of knee-jerk response is often beneficial, the downside of it is that much like bad habits it can also prove to have negative effects. This is where experience can undermine us, leaving us to rely on old or incorrect knowledge which may no longer be relevant in a rapidly changing world.

What is clear is that to both understand and respond to these positive and negative aspects of unconscious knowledge, we must look to the ways in which it is acquired in the first place and to find methods for it to be expressed more explicitly. This is evidently a difficult task when a person essentially lacks 'knowledge of their knowledge' and is unable to express how he/she acquired it, or when precisely it's being accessed. For the moment, this leaves informed researchers or machines to monitor individuals and to make judgements based upon observable evidence. At its simplest, it's possible that under extensive questioning, one might be able to gain insight into how and where this knowledge arose from, but for more difficult cases, invasive techniques may be required, which would still be unlikely to provide a complete picture of such knowledge.

Yet in the entirety of this journey into the unconscious, what is particularly intriguing is not simply the mystery, resilience and potential of unconscious knowledge, but rather the fact that it can also be constructed via unconscious processing. Whether we realise it or not, we are all being influenced by the information that surrounds us.


1. Steele, R. S., and Morawski, J. G., "Implicit cognition and the social unconscious," Theory and Psychology 12, no. 1 (2002): 37-54.

2. Luis M. Augusto, Unconscious knowledge: A survey, Advances In Cognitive Psychology 6 (2010): 117.

3. Ibid., 118.

4. Graf, P., Squire, L. R., & Mandler, G., "The information that amnesic patients do not forget," Journal of Experimental Psychology: Learning, Memory, and Cognition 10 (1984): 164-178.

5. Michael A. Arbib and Giacomo Rizzolatti, "6: Neural Expectations," in The Nature of Concepts: Evolution, Structure, and Representation, ed. Philip Van Loocke (London: Routledge, 1999).

6. Karabanov et al., Dopamine D2 receptor density in the limbic striatum is related to implicit but not explicit movement sequence learning, Proceedings of the National Academy of Sciences 107, no. 16 (2010): 7576.

7. Augusto, 120.

8. Athena Vrettos, Somatic Fictions: Imagining Illness in Victorian Culture (Stanford, CA: Stanford University, 1995), 199.

9. Marshall Cavendish, Encyclopedia of Life Sciences, 2nd ed., vol. 7 (Tarrytown, NY: Marshall Cavendish, 2004), 926.

10. Cesare Lombroso, Guglielmo Ferrero and Nicole Hahn Rafter, Criminal Woman, the Prostitute, and the Normal Woman (s.l.: Duke University Press, 2004), 274.

11. Vrettos, 103.

12. Ibid.

13. Richard M. Perloff, The Dynamics of Persuasion (Mahwah, NJ: Lawrence Erlbaum Associates, 1993), 21.

14. Ibid.

15. Bill Latham, "Valleys of Death: A Memoir of the Korean War," Military Review 92, no. 3 (2012): 102.

16. Augusto, 117.

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Creative Commons License
This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.