Cranial Capacity - A "Numbers Game" for Evolutionists!

"Pea brain", "muscle head" - familiar words to our vernacular which describe mentality, and point to our belief that brain size and intelligence go hand in hand. Since man is at the top of the mental hierarchy of animal intelligence, evolutionists claim fossil support for man's ancestry from a small pongid-size brain. Stephan Molnar (1975, p.56) says, "That the brain space and hence the brain has increased in size during the last two million years of evolution is extremely important to studies of human palaeontology, and comparison on cranial capacity of the different fossils can be useful." Does the study of cranial capacities really support evolution, or has it been a "numbers game" with no significance?

Measuring the Numbers

Cranial capacity has been measured in a variety of ways. Mustard, millet, or flax seeds were used because they approached the closest to the mass of a liquid, but also, small lead shots were commonly used (Montagu, 1960). If mustard seed were used, they were placed into the hollow skull through the foramen magnum by means of a funnel and agitated by the hand or an agitating instrument. When the skull was sufficiently packed, the material was poured into a measuring glass which was again agitated and packed. Different measurements on the same specimen could be made depending upon the way seeds were compressed, the speed with which the seeds were shot in, and the diameter of the neck of the funnel. Another method for measuring cranial capacity which is now used is to make an endo-cranial cast of the specimen, then measure the amount of water the cast displaces.

Indirect measurements can be made with different formulas depending upon sex. Oliver (1969) lists these formulas:

Male: 359.34 + 365 x 10-6 (length x breadth x auricular height).

Female: 296.4 + 375 x 10-6 (length x breadth x auricular height).

Changes are made in the formulas depending upon race and the thickness of the parietal bone.

Cheating With the Numbers

Measuring cranial capacity became important in the Nineteenth Century in the science of craniometry or skull measuring. Paul Broca, who was on the Faculty of Clinical Surgery in Paris, collected a lot of data, thereby gaining respect and support for his research. He so boldly declared:

"In general, the brain is larger in mature adults than in the elderly, in men than in women, in eminent men than in men of mediocre talent, (and) in superior races... other things equal, there is a remarkable relationship between the development of intelligence and the volume of the brain." (Stephen Gould, 1978, p.44).

Of particular interest was that Broca actually felt that he had scientific evidence that women had smaller brains and therefore could not be equal to men in intelligence. After measuring two hundred and ninety-two brains from Paris hospitals, he declared that men had 14% more cranial capacity. (Molnar, 1975, says that women have on the average 10% less cranial capacity.)

One of Broca's colleagues at his school wrote in France's most respected journal of anthropology:

"In the most intelligent races as among the Parisians, there are large numbers of women whose brains are closer in size to those of gorillas than to the most developed male brains." (Gould, 1978, p.48). He went on to describe how women act accordingly.

Later on, in the Nineteenth Century, another cranio-metrician, Samuel George Morton, measured the cranial capacities of various races. He felt that the Swiss skulls had the hallmark of all races having the highest cranial capacities, followed by other whites, with Indians in the middle and Blacks on the bottom. His data is discredited by Gould (1978) because he: 1) Changed methods of measurements from using white mustard seeds to lead shots with Caucasian skulls, giving whites a "leading edge"; 2) He withheld some specimens which he felt "atypical" of that race, and 3) He failed to recognise sexual differences in skulls.

Morton and Broca provided unscientific data to support the racism and sexism of the Nineteenth and early Twentieth Centuries, but because they were sincere and convincing they were accepted by many scientists.

Measuring Different Numbers

Tobias (1970) wrote that the problem with measuring the cranial capacity is that it does not measure the actual mental capacity (i.e. the "thinking part" of the brain). A cranial capacity of 1,000 cc, for example, includes brain tissue plus non-brain material such as roots, trunks of twenty-four cranial nerves, the thick dura mater, two thinner inner coverings called the arachnoid and pia mater, and cisterns which are areas containing fluid, many blood vessels with venous sinuses, blood and cerebrospinal fluid. Thus, Tobias was not so much interested in cranial capacity but brain weight.

However, although brain weight may seem to be ideal, Tobias went on to say that there are too many factors which can alter brain weight at the time of death. A list of them are: sex, body age, nutritional state during development, source of sample, cause of death, time measured after death, temperature at death, the level where the brain was severed for measurement, the presence or absence of cerebrospinal fluid, the presence or absence of meninges, and the presence or absence of blood vessels. Since many of these factors are not recorded during measurements, Tobias (1970) admits that comparative studies of races, sex, etc., have been meaningless.

Measuring Man's Numbers

Basic to the support of the evolution of man's cranial capacity is the current knowledge of cranial variability. Although it is said that man's cranial capacity is around 1300 cc, that is only an average. Various healthy populations contain people who have cranial capacities well into the "fossil man" range. In 1950, O. Schlaginhaufen found a skull of a Menanesian woman with a cranial capacity of 790 cc, which is said to be the lowest on record (Schultz, 1966). Marvin Harris (1971) claimed that the variability of man's cranial capacity starts at 850 cc. Bonin (1963) said that Raymond Dart mentioned in his discussion on his fossil man that he found Bantus with capacities of 511, 519, and 561 cc who were functional as herd boys and farm hands, and although their cranial capacities would equal that of an adult gorilla, it was obvious that they were not pongid in their behaviour. On the other hand, Schultz (1966) claimed that a very large gorilla had been found to have 685 cc cranial capacity. So, as Holloway (1966, p.58) explains it:

"One cc of chimpanzee cortex is not equivalent of one cc of human cortex, nor is it likely that any equivalent measure can be found."

Contrary to Broca's statement that eminent men had larger brains than men of mediocre talent, there is no correlation of cc of brain and mental capability in normal people (Gould, 1974). Eminent men such as Anatole France, Franz Joseph Gall, and Leon Gambatta are known to have had 1000-1100 cc of brain. They were just as intelligent as Oliver Cromwell and Lord Byron who had cranial capacities of 2200 cc and above.

Measuring Fossil Man's Numbers

The fossil history is claimed to support the evolutionary theory that man's ancestors stemmed from a small chimpanzee brain australopithecine, to the "normal" sized brain of Cro-Magnon man, as seen in the table below:

Chimpanzee 393
Gorilla 506
Australopitecus 494
Homo habilis 656
Homo erectus 935
Cro-Magnon Homo sapiens 1370

Average Cranial Capacities of Fossil Hominids

Although the table shows a convincing argument for the evolution of man's cranial capacity, there is a lot of data which contradicts this that tends to be overlooked.

First of all Homo erectus skulls, of which Java Man and Peking Man are examples, were dated about 500,000 years B.C. and were said to average approximately 950 cc. But, one of the oldest Homo erectus skulls, OH9, dated at first to be 900,000 B.C. (Laskers, 1973), is now dated 1.2 million years (Nelson, 1985). Nicknamed 'Chellean Man', he is noted for his huge brow ridge, a "primitive" characteristic, yet he has the largest cranial capacity (1067 cc) of all early H. erectus specimens (Nelson, 1985). Another skull, 'Solo Man', which is said to resemble OH9, is dated 300,000 - 600,000 B.C. and has 1035 cc cranial capacity. So the older the dating of the fossil man doesn't mean the smaller the cranial capacity.

Contrary to belief, Homo erectus lived contemporaneously with many australopithecines. In South Africa a small mandible is found in the site of an earlier australopithecine. Nelson (1985) wrote concerning KMNER 3733, a Homo erectus skull claimed to have lived around the time of Chellean Man:

"A puzzling aspect of the KMNER 3733 is that it was found in the geological bed with robust australopithecines A. boisei and perhaps A. africanus as well (Nelson, 1985, p.497). Thus, it appears that man's supposedly immediate ancestor lived with his pongid brain progenitors."

Not all H. erectus skulls contained small brains. One such example is Vertesszollos Man, dated 350,000 - 400,000 B.C., estimated to have a cranial capacity of approximately 1400 cc which is above the average human cranial capacity (Day, 1977). Therefore, some of our supposedly immediate ancestors could have had above average cranial capacities.

Neanderthal Man, which is dated older than Cro-Magnon Man, had an average cranial capacity of 1470 cc, the latter of which had 1370 cc (Lavelle, Shellis, and Poole, 1977). Poirier (1974, p.94) says:

"There has been an actual reduction of approximately 300 cc of brain since the time of the Neanderthals." Neanderthals supposedly evolved 250,000 B.C., so it would appear that man has evolved the "wrong" way since that time.

It has been argued by evolutionists that H. erectus must have been Cro-Magnon's immediate ancestry because no modern type has been found with the earliest Homo erectus findings. However, skulls which have been found in plio / pleistocene strata with modern features and "normal" cranial capacity have not been accepted because they were "out of place". Lists of these findings are in Shute (1961) and Bowden (1977).

Changing numbers

Estimates of the cranial capacities of various hominids have not always remained the same. Some estimates have changed because of different methods used, but some seem to be influenced by their place in their phylogenic interpretation.

One example is Oreopithecus, which had long arms like an ape and some monkey characteristics, but above all, homonid traits such as small canines, large iliac blades and a forward-placed foramen magnum, which indicated that the organism might have walked upright (Rosen, 1974). In 1960 when the crushed Oreopithecus skull was measured with direct and some indirect methods, its cranial capacity measured 490-640 cc (Strauss and Schon, 1960). This was close to the range of australopithecines and swayed scientists to believe Oreopithecus filled the gap of hominid evolution in the Miocene era.

In 1963, the Yellow Version of the Biological Science Curriculum Studies taught in its section on human evolution:

"Subsequent careful studies, which require a great deal of time, confirmed that Oreopithecus has so many human-like, rather than ape-like features that most authorities are inclined to place it as the earliest representative of the family of man - the Hominidae (John Moore, 1963, p.661)."

This view is not accepted today, and Oreopithecus is mentioned very briefly in most textbooks as a swamp ape possibly related to the Apidium, a squirrel-like anthropoid. Szalay and Berg's (1974) most recent estimation of Oreopithecus's endo-cranial volume was about 200 cc, which is more in keeping with its monkey-like characteristics. Scientists literally made a monkey out of a man.

Piltdown Man, which was first viewed as a "missing link" between apes and man, had cranial fragments which could be rearranged in various ways to alter his estimated cranial capacity. In December, 1912, Woodward Smith reconstructed its skull and declared Eoanthropus, as he was then called, as having an estimated cranial capacity of 1070 cc. This estimate was within the Homo erectus range. However, when its jaw was made to fit its reconstructed cranium, its cranium had to be "expanded" since the jaw of a chimpanzee, which it was later proven to be, is much larger than a man's. So in 1922 after final reconstruction, the cranial capacity of Piltdown Man rose to 1200 cc. At that time evolutionists concluded that man's brain evolved in Britain faster than his other ancestral characteristics. Later when Piltdown Man was discovered to be a hoax, australopithecines changed evolutionists' position back to the small-brain-to-big-brain sequence of evolutionary progression.

An example of a more recent change of cranial capacities was done by Ralph Holloway (1974). He took endo-cranial casts, and by the water replacement method made more accurate cranial capacity estimates of fossil hominids. He found that the South African australopithecines were estimated to be substantially smaller than had been previously estimated. Those estimates which exceeded 500 cc were estimated below 450 cc. (Duffet, 1983, showed that many estimations of these hominids have been lowered over the years.) Java Homo erectus skulls were estimated to have higher cranial capacities. Thus, Holloway increased the cranial gap between Homo and australopithecines, man's supposedly ape-like ancestors.

Adding Numbers

Heavy emphasis so far has been placed on cranial capacity per se and not brain-body weight ratio. However, if one compares the human statistics with other primate statistics, the supposedly closest relatives of man do not necessarily have the closest brain-body weight ratio (Molar, 1975). Man has a 1:47 (1:50, Rose, 1984) ratio, but his supposedly closest relative, the chimpanzee, has a ratio of 1:13. The gorilla has a brain-body ratio of 1:42, but the night monkey with 1:85 and the capuchin monkey with 1:83 show the highest primate brain-body ratio.

Some non-primates have high brain-body ratios closer to man than other primates. The top of the list is the bottle nose dolphin with a 1:67 brain-body ratio (Lilly, 1961), and near the top is the house mouse with a brain-body ratio of 1:40 (Tobias, 1976).

The low cranial capacity of women which Broca used to show women's inferiority to men can be seen in a different prospective when brain-body ratio is considered. Relative brain size which is (relative brain size = cranial capacity/body weight x 100) for an eighteen-year-old male is 2.37 and for an eighteen-year-old female is 2.482 (Duffett, 1983).

An experiment was done to increase cranial capacity of rats to see if it would affect intelligence. Zamenhof (McLeod, 1983) injected somatotrophin into pregnant rats to increase brain cell growth and thereby producing 70.4% superbrain foetuses. On psychological testing there was no difference in performance and in some cases worse. So, artificially increasing the brain-body ratio, at least in this study, doesn't increase intelligence.

Thus, it is found that brain-body ratio seems to be as equally meaningful as cranial capacity alone. But still, many attempts have been made to apply brain-body ratio to fossils.

Relatively few post-cranial bones have been found with fossil men. Those found have indicated that fossil hominids such as the australopithecines are of very small stature. Therefore, although they have small cranial capacities, evolutionists conjecture that their brain-body ratio would "elevate" them to a cranial capacity worthy of the title "ape-men".

Gould (1974) did a brain-body ratio analysis of various hominids. He noted that mammals have cranial increase of about 2/3 the rate of the body because the body surface area of mammals also increases by about 2/3. However, a man's cranial increase to body size is much higher and definitive of Homo. According to brain-body ratio, then, australopithecines and early Homo habilis (recognised by many as the same as the former) conform to the mammalian brain body-ratio, whereas KMNER 1470, early Homo, Homo erectus and Homo Sapiens have a human brain-body ratio.

Summing It Up

Cranial capacity as a measure of intelligence has never been proven: it has only been a "numbers game". Nineteenth Century scientists used statistical measurements of cranial capacities to support their belief in racial, sexual, and class inferiority. Their numbers support their "game". However, numbers ascribed to any population alive or fossilised can be considered speculative since the numbers can change due to new measured parameters, new fossil findings, or new discoveries. So the numbers and the rules of the "game" can change. The view today that "superbrain" intelligent man evolved from an ape-size stupid brain ancestor may be just a numbers game to support evolutionists' biased view. Bonin (1963, p.76), an evolutionist, shows his confusion by saying:

"...that the brain increases in size as we go from australopithecines to modern man, or to the upper Paleolithic for that matter, is quite obvious and of course very gratifying. But the meaning of the increase is again not quite clear because as we all know, brain size as such is a very poor indicator of mental ability..."

Even if some day evolution would be proven wrong, the "numbers game" will still be with us. Just the players and rules will change.

by Douglas S. Jue


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Source: 'Bible Science Newsletter: Contrast - The Creation Evolution Controversy', Vol.5, No.3, May-June 1986