Tuesday, February 01, 2005

Darwin & Hebb

The title of this post could also be called "lazy blogger" because the following entry is actually part of an assignment for a class this past term. I'm posting it because it provides a bit of info on Darwin and Hebb, as well as my thoughts regarding the importance of each. Also, that I've been busy lately. Upon a second reading, I'm not as happy with the piece as I previously was, but so it goes.

1b)It has been suggested that Hebb’s contributions to psychological science will eventually achieve the status that Darwin’s ideas have achieved in biological science. Defend or critique this suggestion. (747 words, there was a limit of 750)

Donald O. Hebb is surely one of the greatest psychologists of the 20th century, but he will likely never attain the status of Charles Darwin, the man credited with the theory of evolution by natural selection. What follows shall be a brief review of Hebb’s contributions, a short examination of the impact of Darwin’s theory and lastly a comparison between the two great men of science; it will be apparent that though Hebb was admirable in his own right, to achieve a Darwinian status is unlikely.

Over a long and varied career, Hebb was involved in many different research areas and impressively made substantial contributions to most of them. In his work with brain lesioned patients, Hebb believed the Standford Binet and Wechsler intelligence scales were inappropriate because they measured general alterations of intelligence. Consequently, Hebb co-developed two new tests that would be able to assess the area lesioned with greater specificity. The results of these test provided the first evidence that the right temporal lobe was involved in visual recognition and that removal of the frontal lobes do not greatly affect intelligence. Following this work, Hebb began to investigate the development of rat intelligence with Kenneth Williams. Together they developed a variable path maze, subsequently called the Hebb-Williams maze, which has been widely used to study learning in animals. Utilizing this maze as well as altering a rat’s environment, Hebb was able to demonstrate that early experience can have profound effects on cognitive abilities later in life. Hebb’s work lead to programmes to help underprivileged children with enhanced focus on scholastic areas early in their life. In addition to the incredible discoveries aforementioned, there is still Hebb’s most famous contribution: the idea that the strength of transmission can modify existing synapses. The idea of Hebb cell assemblies has provided a framework for thinking about learning, memory formation, emotion, motivation and even computer models of the brain. (Brown & Milner, 2003). Hebb’s work, diverse and noteworthy, establishes him as an eminent psychologist, but it was not revolutionary enough to change the thought of being.

Charles Darwin’s book, “On the Origin of Species,” changed the world. The 1859 book put forth a new addition to the current theories of evolution, that of descent with modification. The theory was extraordinarily significant because it was able to undermine the Argument from Design, and thusly indicated that humans were just another animal, another branch in the tree of life. Prior to Darwin, the notion of life increasing in complexity over millions of years was possibly unheard of and definitely not popularized. By providing a way of thinking about how complexity could arise, Darwin offered an actual rebuttal to one of the main arguments for believing in God. Darwin indicated that life did not need a God; it could do it on its own, through a natural, mindless, purposeless process no less! To imply there is no God and your ancestor was a monkey was not well received by Darwin’s contemporaries. There is the story of a famous debate between T.H. Huxley and Wilberforce, the then Bishop of Oxford. Wilberforce asked Huxley if he would prefer to think of himself descended from an ape on his grandfather's or grandmother's side? To this Huxley replied that he was not ashamed of a simian ancestry but "he would be ashamed to be connected with a man who used great gifts to obscure the truth." Supposedly, among the 7000 people listening, a woman fainted and had to be carried out (Brooke, 2001). This never happened with Donald Hebb’s idea of synaptic plasticity. The lack of publicity and more specifically public controversy is why Hebb’s contributions will never achieve the status of Darwin’s.

Charles Darwin and Donald O. Hebb were extraordinary scientists who greatly impacted their field of study. Both men have made contributions that have been mainly forgotten: Hebb’s intelligence tests or Darwin’s four-part monograph on all barnacles then known. Both men changed the way their discipline thought after their works were received; yet both lacked detailed evidence. There are two differences though: publicity and impact. Hebb has said, “The general idea is an old one…” and did not go to great lengths to ensure everyone heard his thoughts. Alternatively, Darwin’s associations with Huxley and other intellectuals of his time made sure he received all the credit and great publicity. As for impact, Hebb’s synaptic plasticity changed how psychologists and neuroscientists thought about the brain; Darwin’s theory of evolution changed how people saw the world.

Brooke, J.H. (2001). Science & Christian Belief Vol. 13, No 2, pp.127-141.


Anonymous Anonymous said...

This comment is marginally related. I thought you would get a kick out of this paragraph written by Robert Park.


Manufactures are required to include warnings on labels. Why not text book publishers? Besides, the stickers Cobb County wanted on biology texts weren't exactly wrong evolution really is "just a theory." http://www.aps.org/WN/WN05/wn011405.cfm Science
is open. If someone comes up with a better theory, the textbooks will be rewritten. Although requiring warning labels on medicine bottles is vital, on books they become official doctrine.

Several readers suggested stickers for bibles in Cobb County:

"This book contains religious stories regarding the
origin of living things. The stories are theories, not
facts. They are unproven, unprovable and in some cases
totally impossible. This material should be approached
with an open mind, and a critical eye towards logic and


1:03 PM  

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