The Physics Factbook
Edited by Glenn Elert -- Written by his students
An educational, Fair Use website
|Nelson, Gideon E. Fundamental Concepts of Biology. New York: Wiley, 1982: 262.||
|"Brain." Grolier Multimedia Encyclopedia. CD-ROM. 1995.||"The average human brain at weighs 390g (14oz); its average maximum weight, reached at age 15, is 1315g (46oz)."||1,315 g
|Brain Size, Body Weight and Intelligence. The High North Alliance brochure; "Living off the Sea, Minke Whaling in the North East Atlantic", February 1994.||[see table below]||1,500 g|
|Chudler, Eric H. Brain Facts and Figures. University of Washington.||
|An Introduction to the Brain. A Relationship Between Evolution, Genetics, Morality, Ethics, Psychology, Education, and Culture. onelife.com.||"The size of the modern human adult brain is about 1350 cc."||1,350 g|
The mass of a newborn human brain is about 350-400g. The mass of an adult human brain is about 1,300 to 1,400 g. The brain makes up about two percent of the human"s mass. Its average width is about 140 mm, average length is about 167 mm, and average height about 93 mm.
According to the Grolier Multimedia Encyclopedia, "A theory has been proposed which states that behavioral capacity, a broad term indicating intelligence, is related not to the size of the brain but to the index of cephalization -- the amount of brain in excess of that required for transmitting to and from the brain." Another source (High North Alliance) states "neither absolute brain weight nor the relationship between brain weight and body size provide us with sensible criteria for comparing the intelligence of different species". Therefore meaning, the size of the brain doesn't necessarily determine the intelligence of that species. The table below shows this; because we know that humans are more intelligent than the other species on the chart, yet our brains are considerably smaller than most.
Species Brain weight Body weight Brain weight (gram) (tonne) as % of body weight Man 1500 0,07 2,1 Bottlenose dolphin 1600 0,17 0,94 Dolphin 840 0,11 0,74 Asian elephant 7500 5,0 0,15 Killer whale 5620 6,0 0,094 Cow 500 0,5 0,1 Pilot whale 2670 3,5 0,076 Sperm whale 7820 37,0 0,021 Fin whale 6930 90,0 0,008 Mouse 0,4 0,000,012 3,2
|Source: High North Alliance|
Rachel Scott- Rosenbluth -- 2003
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