A human brain being measured  with a measuring tape. Human Intelligence

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Charles Darwin

(February 12, 1809-April 19, 1882)
British naturalist

Portugees version



  • As a youth, he was taught by his sisters, private tutors and occasionally by his uncle (the father of his cousin, Francis Galton)
  • Dr. Butler's school in Shrewsbury, England (1818-1825)
  • Studied medicine at Edinburgh University (1825-1827)
  • Studied for the ministry at Christ's College, Cambridge (1828-1831)


  • Served as an unpaid naturalist aboard the British Navy ship H.M.S. Beagle (1831-1836)
  • Darwin was financially independent, and spent the remainder of his career experimenting, writing and lecturing (1836-1882)

Definition of intelligence

"…a high degree of intelligence is certainly compatible with complex instincts, and although actions, at first learnt voluntarily can soon through habit be performed with the quickness and certainty of a reflex action, yet it is not improbable that there is a certain amount of interference between the development of free intelligence and of instinct,--which latter implies some inherited modification of the brain. Little is known about the functions of the brain, but we can perceive that as the intellectual powers become highly developed, the various parts of the brain must be connected by very intricate channels of the freest intercommunication… (Darwin, 1871, 1896, p. 68)”

Major Contributions

  • The Theory of Natural Selection

Ideas and Interests

The importance of Charles Darwin's contributions to the history of intelligence testing cannot be overemphasized. Evolutionary theory is central to the arguments of many of the psychologists profiled on our site. (To sample these ideas, please see our profiles of Cyril Burt, Francis Galton, Henry Goddard and Arthur Jensen). Without Darwin (and his contemporary Alfred Russel Wallace) there would be no nature vs. nurture debate.

Darwin devoted several pages of his autobiography to a discussion of his family and their respective contributions to his education. He describes their efforts to tutor him, and suggests that their diverse interests provided ample opportunity for him to learn vicariously. However, it is not surprising that he attributed his own intellectual success to nature, not nurture. He expressed his beliefs succinctly when speaking about his brother, Erasmus Darwin:

…I do not think that I owe much to him intellectually-nor to my four sisters…I am inclined to agree with Francis Galton in believing that education and environment produce only a small effect on the mind of any one, and that most of our qualities are innate (Darwin, quoted in Barlow, 1958 p. 43).

Darwin believed that intelligent behaviors developed from the primitive instincts of our nonhuman ancestors, and that the difference between human intelligence and animal intelligence is a matter of degree, not of kind: In his introduction to a book chapter on the evolution of mental powers, he stated: "My object in this chapter is to shew that there is no fundamental difference between man and the higher mammals in their mental faculties (Darwin, 1871, 1896 p. 66).”

In TheDescent of Man (1871/1896), Darwin presented numerous examples supporting his contention that humans and nonhuman animals share cognitive attributes like wonder, curiosity, long-term memory, the ability to pay attention, imitate the behavior of others, and to reason (Darwin, 1871/1896, p.65-113).  As one illustration, he offered the story of an aggressive fish that took three months of smashing into a pane of glass separating it from other fishes to learn that it could not get through. Darwin suggested that although a monkey would have learned the same thing after only one trial, the important fact is that both creatures share the same ability to learn from experience.  Those fishes or monkeys who could not learn would be "selected against" by nature, and would not pass on their genes. Only the intelligent genes would remain in the pool, thus gradually increasing the overall intelligence of each species. Darwin held that the human mind evolved into its present advanced state by the same process. When speaking of our moral and intellectual abilities he said:

These faculties are variable; and we have every reason to believe that the variations tend to be inherited. Therefore, if they were formerly of high importance to primeval man and to his ape-like progenitors, they would have been perfected or advanced through natural selection (Darwin, 1871, 1896, p. 128).

Those scholars who are interested in the history of the eugenics movement will find some arresting quotes in the fifth chapter of The Descent of Man. This chapter, titled "On the Development of the Intellectual and Moral Faculties During Primeval and Civilized Times" provides source material for many of the eugenicist arguments. For example:

With savages, the weak in body or mind are soon eliminated; and those that survive commonly exhibit a vigorous state of health. We civilized men, on the other hand, do our utmost to check the process of elimination; we build asylums for the imbecile, the maimed, and the sick; we institute poor-laws and our medical men exert their utmost skill to save the life of every one to the last moment…Thus the weak members of civilised societies propagate their kind. No one who has attended to the breeding of domestic animals will doubt that this must be highly injurious to the race of man. It is surprising how soon a want of care, or care wrongly directed, leads to the degeneration of a domestic race; but excepting in the case of man himself, hardly any one is so ignorant as to allow his worst animals to breed (Darwin, 1871, 1896, p. 133-134).

However, it would be unfair to suggest that Darwin condemned these merciful acts; that was not the intention of the quote presented above. He was simply providing evidence for the theory that humans have evolved a more sophisticated moral sensibility than other animals. In the passage following the quote above he states that eliminating acts of human sympathy would result in the "deterioration in the noblest part of our nature." Even though some intelligence theorists advocating the hereditarian position have used Darwinian ideas to support eugenicist goals like forced sterilization, it is very likely that Darwin himself would have objected to these practices:

…if we were intentionally to neglect the weak and helpless, it could only be for a contingent benefit, with an overwhelming present evil. We must therefore bear the undoubtedly bad effects of the weak surviving and propagating their kind…(Darwin, 1871, 1896, p. 134).

Selected Publications 

Darwin, Charles. (1877). A biographical sketch of an infant. Mind, 2, 285-294.

Darwin, C. (1859, 1985). The origin of species by means of natural selection; or, the preservation of favoured races in the struggle for life. New York: Penguin. A full-text version is available online from http://www.literature.org/authors/darwin-charles/

Darwin, C. (1871, 1896). The decent of man and selection in relation to sex. New York: D. Appleton and Company.


Darwin, C. (1887, 1958). The autobiography of Charles Darwin. In N. Barlow (Ed.), The autobiography of Charles Darwin. London: Collins.

Darwin, F. (Ed). (1887). The life and letters of Charles Darwin. London: John Murray.

Encyclopedia Britannica Online " Darwin, Charles" Retrieved from http://www.britannica.com/eb/article?eu=117775&tocid=0&query=charles%20darwin June 8, 2002.

Legassé, P. (Ed.). (2001). Darwin, Charles. The Columbia Encyclopedia ( 6th ed.) [Online Version]. New York: Columbia University Press. Retrieved from www.bartleby.com/65/da/DarwinCR.html June 5, 2002.

Stefoff, R. (1996). Charles Darwin and the evolution revolution. Oxford: Oxford University Press.

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