Bigfoot Encounters

by Gordon Strasenburgh

This article gives a summary of the biomechanical analyses by various scientists of the Patterson-Gimlin Film. Strasenburgh, who displays a great knowledge in the field of human evolution, attempts to identify the film's subject as a large surviving australopithecine --Paranthropus or Australopithecus robustus --a view he has made in previous writings. Thus, he takes a position different from the other two major alternatives, in terms of the level of humanity and identification of the creature in the film. The common view in the West is that a less human, Gigantopithecus is the creature in question. Some Russian authorities, however, consider it to be a more human Neanderthal man.

In 1967, nine years after the term Bigfoot was coined in response to large, man-like footprints found in northern California, the late Roger Patterson exposed 29 feet of 16mm color motion picture film. On the film is the image of a large, heavy-set, hairy hominid. Most anthropologists who have viewed the film agree that the image is crested and has pendulous breasts. This paper will review the circumstances of the film, the analyses, which the film has undergone, and their contexts, North American anthropological attitudes pertinent to the question, and will suggest further analyses which the film might be properly subjected to.

The Patterson-Gimlin film is almost universally regarded by those interested in and knowledgeable about the Bigfoot or Sasquatch phenomenon as genuine. There are two reasons. One is that the image on the film corresponds to the verbal descriptions recorded previously. The image is that of "an animal bearing the unmistakable likeness of humanity," as a report of a sighting reads in the May 9, 1851 Memphis Enquirer (..a copy may be examined at the Library of Congress).

The article continues: "He was of gigantic stature, the body being covered with hair and the head with long locks that fairly enveloped the neck and shoulders. This singular creature has long been known traditionally in St. Francis, Green, and Poinsette Counties, Arkansas, sportsmen and hunters having described him so long as seventeen years since." In an 1870 California newspaper a pair of hairy hominids are described, one of them "a female, unmistakably" (Green 1973a:120).

Whatever the reason that one of the hairy pair was unmistakably identified as a female in 1870, a sighting that took place in 1955 clarifies the record. In 1957 John Green had the late William Roe put down his recollections in a sworn statement.

My first impression was of a huge man, about six feet tall, almost three feet wide, and probably weighing somewhere near 300 pounds. It was covered from head to foot with dark brown silver tipped hair. But as it came closer I saw by its breasts that it was female. And yet, its torso was not curved like a female. The head was higher at the back than at the front (Green 1973a: 17-18).

Patterson's involvement began after road-building crews in the Bluff Creek area of northern California found large footprints around their construction equipment. He decided to try to get a film of the creature. In the eighth year of his search he claimed success. Here is how he described it.

Bob Gimlin, a friend of mine, and myself had been in the area (12 miles northwest of Orleans, California) a little over a week, when riding horseback up a creek bottom the afternoon of October 20, 1967, we encountered this creature. My horse smelled it, jumped and fell. I got the camera out of the saddle bag, ran across the creek and we were able to get 29 feet of 16mm colored film. We tracked the creature for about three miles, only to lose its tracks in the extremely rough terrain and heavy undergrowth. Most of the film is very clear, allowing the scientific and movie experts to see the muscle movement of the Bigfoot creature. Footprints of the creature, preserved in plaster casts made by myself and Bob at the time, and by others who visited the area later, measured 14~A inches from heel to toe. (..from a 4 pg form letter by Patterson as Executive Director of the Northwest Research Association around 1970)

Ten years later there are four analyses of the Patterson-Gimlin film on record. Three are favorable, and are the second reason why investigators consider the film genuine. We will review the four and the context of each in the order in which they were published.

Analyses of the Patterson-Gimlin Film
The first analysis was conducted by D.W. Grieve, Reader in Biomechanics, Royal Free Hospital School of Medicine London. Its purpose was" establish the extent to which the creature's gait resembled or differed from human gait" (Napier 1972:215). In addition to the Patterson-Gimlin film proper, Grieve examined a sequence showing a 6 foot 5.5 inch tall human walking over the same course. By comparing these two films, he arrived at a height, weight, and foot length of, respectively, 6 feet 5 inches, 280 pounds, and 13.1 inches for the image of the Sasquatch.

Grieve concluded:
If the film was taken at 24 fps (frames per second) Sasquatch walked with a gait pattern very similar in most respects to a man walking at high speed... The shoulder breadth however would be difficult to achieve without giving an unnatural appearance to the arm swing and shoulder contours. The possibility of fakery is ruled out if the speed of the film was 16 or 18 fps. In these conditions a normal human being could not duplicate the observed pattern, which would suggest that the Sasquatch must possess a very different locomotor system than that of man (Napier 1972:220).

The second analysis was undertaken by Grover S. Krantz (1972b), to test his earlier hypothetical reconstruction of the Sasquatch foot and ankle pivot (Krantz 1972a). In addition, Krantz used the image to estimate the volume and weight of the body. He found the stature to be "almost exactly 7 feet," by using the average of five footprint casts (14.25 inches) as a known distance, as well as by comparing the Patterson-Gimlin film to the film of the man walking in the footprints of the Sasquatch. Employing three independent methods, Krantz arrived at estimated weights of 471, 476, and 506 pounds.

After examining the frames that show the foot, Krantz concluded that the image shows ankles that are set further forward than those of human beings. Specifically, he found the Sasquatch ankle forward of the heel tip 31% of the total length of the foot, as opposed to 25% in the typical human. In all, Krantz found the Patterson-Gimlin film image to be consistent with data in the form of footprint casts he had previously examined and analyzed, and with eyewitnesses' estimates of height and weight previously recorded.

The third man to analyze the film was Dmitri Donskoy, Chief of the Chair of Biomechanics, Union of Soviet Socialist Republic's Central Institute of Physical Culture Moscow. It is described as a "qualitative biomechanical analysis." Donskoy did not address either the question of the exact dimensions of the image or the speed at which the film might have been taken. He concluded:

Since the creature is man-like and bipedal its walk resembles in principle the gait of modern man. But all its movements indicate that its weight is much greater, its muscles especially much stronger, and the walk swifter than that of man... At the same time, with all the diversity of human gaits, such a walk as demonstrated by the creature in the film is absolutely non-typical of man (Hunter and Dahinden 1973:191192).

The fourth analysis of the film was made by Geoffrey Bourne, Director, Yerkes Regional Primate Center, Emory University, Atlanta. As a portion of the hour long "MONSTERS! Mysteries or Myths?" (..directed by Robert Guenette) produced by Wolper Productions in association with the Smithsonian Institution, it was broadcast on network television the evening of November 25, 1974, and reportedly viewed by 30,000,000 North Americans. Bourne informed me by telephone that he had viewed the Patterson-Gimlin film several years earlier. He said the request by Wolper that he analyze the film, his second viewing of it, and the recording of his conclusions all took place in the space of a few days. The following is a transcript of his statement as provided by the Smithsonian Institution:

Well, you know, that looks to me very much like a human walk. Its gait is very much of a human type gait and also when you look at its feet as it walks, the under surface is much too light-colored for an animal with this kind of dark fur. And furthermore, it seems to have the characteristics of both male and female---the head has a big crest on it like a male gorilla does--and this crest is called a sagittal crest. Now, this creature also has pendulous breasts which is a female characteristic and the breasts are covered with fur and in all other primates the breasts are actually either bare or very sparsely haired. So for these reasons alone, I would have very grave doubts about the authenticity of this particular animal.

Testing Hypothesis
There are two testable, mutually exclusive hypotheses concerning the image on the Patterson-Gimlin film. It is genuine and graphic evidence of a species of hominid unknown to science, or it is, in a word, a hoax. The actual mechanics of the hypothetical hoax in turn give rise to operational hypotheses from the plausible "man in an ape suit" to the rather fanciful "hoaxers hoaxing hoaxers." Although the reader is invited to speculate to his heart's content on any scheme which he honestly believes would replicate the Patterson-Gimlin film and the published analytic response to it, we shall limit ourselves here to the basic question which the Patterson-Gimlin film logically raises: Is the image that of a real hominid, or is it not?

For all practical purposes the first three analyses were published simultaneously. They present, therefore, three independent judgments of the Patterson-Gimlin film, which do not rely upon or take into account earlier study and conclusions. Oddly enough, Bourne's analysis, undertaken a year or more after the publication of the first three analyses, also seems to have been conducted without reference to the others. The three may be characterized as a conditional vote of confidence, and one vote of no confidence in the validity of the Patterson-Gimlin film. Let us compare the conclusions and the common questions they address, and examine further questions they raise.

The first question concerns the dimensions of the image. Krantz finds them to be impossibly large for a human masquerade and consistent with numerous eyewitness reports in North America. Donskoy finds them to be suggestive of a much greater weight than that of a typical human being. Grieve finds them to be within the upper limits of human variation, with the caveat that the shoulders seem disproportionately broad. Bourne does not comment on the dimensions of the image.

The second question arises from the movement of the image. Bourne finds it "very much of a human type gait." Donskoy agrees with Bourne "in principle," and then goes on to enumerate differences, which lead him to the conclusion that the walk of the image is "absolutely non-typical of man." Grieve detects a similarity between the gait of the image and that of man only if the film were taken at 24 fps or some higher speed. Film speed does not, however, bear upon the appearance of the arm swing and the shoulder contours. Krantz limits himself to the observation that the apparent pivot point of the ankle differs from that of the average man.

The question of film speed has been debated at some length. Patterson's camera was capable of 16, 18, and 24 fps. Napier (1972:94) suggests 24 fps because it is best suited for television transmission, and Patterson acknowledged his desire to have his film broadcast on TV. Napier also reports that Patterson could not recollect at what speed the film was taken. Green (1973b:70) reports Patterson finding his camera set at 18 fps on checking it after the excitement of the moment had quieted, although it was his custom to set it at 24 fps.

These various conclusions, taken together, suggest that in terms of size, proportion, mechanical structure, and movement, the image on the Patterson-Gimlin film cannot be explained by any known agency unless the film speed were 24 fps or greater. None of the four analysts find any evidence that a machine is to be found behind the Patterson-Gimlin film image. None of the four analysts find any evidence that the image might represent a masquerade by any known animal other than man. And three of the four analysts find reason to doubt that the image is that of a human masquerade. If it cannot be said that the preponderance of the analytic results disproves the widely accepted hypothesis that the film is a hoax, there is little, if any, evidence in the published record to support that hypothesis.

What of the anthropological point of view? How does the film fare when the unknown hominid hypothesis is tested?

The first step in the anthropological approach to the film image is best expressed as a question--a question that every anthropologist ought to ask himself. Would I have advised a hoaxer in 1967 to achieve the image of a large, heavy-set hominid with obvious breasts and a sagittal crest? And why? Green (personal communication) has suggested to me that a scientist's inability to conceive of a hoaxer arriving at a complex set of characteristics is highly circumstantial evidence that the hoaxer could not have done so. In the case of the Patterson-Gimlin film, though, I think a valid distinction can be made between what any human being might have known in 1967 and the ability to foresee what would be discovered in the decade following.

The second step in the anthropological approach is as simple in concept as it is controversial in operation. To test the unknown hominid hypothesis, one has only to compare the data, which can be gleaned from the Patterson-Gimlin film image to the sum of data, which is available on hominids. Although it is a trivial matter, we might begin by observing that human hominid footpad color, despite great variation in the predominant skin pigmentation is uniformly light. (Krantz makes the same point in Guenette's updated broadcast in March, 1977). The pendulous breasts of the film image are an exclusive characteristic of hominids. Indeed, Morris' (1967) hypothesis that they are an integral part of hominid evolutionary development appeared in the same year the Patterson-Gimlin film was taken. I have not examined the film frame by frame, but Dmitri Bayanov (personal communication) informs me that by doing so one can ascertain a fiat facial profile. Green (1973a: 71) concurs on this point. If they are correct, then the Patterson film image exhibits three diverse hominid characteristics in addition to its habitually erect, bipedal locomotion pattern.

Now let us proceed to the heart of the matter from the anthropological point of view. Is the sagittal crest of the Patterson-Gimlin film image a positive or a negative indicator within the framework of the unknown hominid hypothesis?

Because the question of the significance of the crest occurs in an apparently controversial context, I would first like to make my position clear. If I had not been aware of the Australopithecus robustus in 1969, I seriously doubt that I would have given Sasquatch a second thought. One could, in that year, visit the Explorer's Hall of the National Geographic Society and view the skull of Australopithecus (Zinjanthropus) boisei revolving on its pedestal to the recorded statement that this was man's earliest known fossil ancestor. I am satisfied that A. robustus (often called Paranthropus) had admirably withstood the test of time during an unprecedented period of burgeoning hominid fossil evidence in Africa.

Robinson's recent (1972) erection of a paranthropine subfamily to accommodate A. robustus and Gigantopithecus has great merit as well. With it convergence is relieved of the responsibility of producing two graminivorous hominoids with overlapping geographical ranges in a relatively short period of time. And the tuberculum sexsum of the A. robustus molars, the Gigantopithecus
molars (Simons, personal communication), and at least some of the Gigantopithecus blacki molars, is transformed from the least likely product of convergence to a possible diagnostic trait at the subfamilial level, rather than at the generic level, as Robinson first hypothesized (1956). If a graminivorous paranthropine represents the hominid archetype out of which Homo sprang as Jolly (1970) and Robinson (1972) suggest, it is proper to conceive of Gigantopithecus as a hominid as large as, if not larger than, the giant of the pongids, the gorilla.

We are far more certain however that Australopithecus robustus, who was relatively taller and most robust than contemporary Australopithecus africanus, was a bona fide hominid. If we regard the fossil remains of A. robustus as anything other than the male of the species. A. africanus, then A. Paranthropus, one of only two known hominids, appears to have been crested in both sexes. "Such a crest is present in every full adult individual so far found in which the relevant region is known" (Robinson 1972:226).

Alternatively, there is no concrete evidence to be found in support of the hypothesis that the female A. robustus, like her pongid cousins, was crestless.

Anthropological Attitudes
There seems to me to be an unpublished controversy of some magnitude concerning Australopithecus robustus. I have come to the conclusion that by whatever name, the other hominid is generally regarded as an embarrassment by the anthropological community. The discussion of the genus (or species, if you prefer) is often fanciful when it is mentioned in more than passing. The hypothesis which accounts for the extinction of Australopithecus robustus by Homo erectus lacks fossil evidence and good sense as well.

Here, for example, is how Napier (1972:173) opens his chapter on the relationship between Sasquatch and fossil evidence:

Correlating 'monsters present' with 'monsters past' is a favorite exercise of their devotees. As a means of rationalizing an 'therwise unlikely story, it has much to commend it. By postulating that a monster is a relic form --a holdover from the past --monster fans feel absolved from the necessity of explaining how such an outrageously unsuitable creature has evolved in the light of the present day ecology. Actually, of course, there is still the obligation, often ignored, of explaining how an archaic form has achieved the remarkable feat of surviving beyond its time [emphasis added].

Because Napier is the leading, anthropologist to have discussed the question of Sasquatch in published form, I conclude that this rather value-laden paragraph represents a relatively moderate position on the question.

Aguirre (1974) and Poirer (1974) also seem to question the propriety of searching for correlations between reports of unknown hominids and fossil species, although their response to Porshnev (1974) represents a somewhat different context.

Yet, if we are to seriously test the hypothesis that the Patterson-Gimlin film is evidence of an unknown hominid, how can we possibly avoid examining every shred of evidence concerning hominid evolutionary history which has been amassed over the past century?

Alternatives to A. robustus
However profitable the inclusion of Gigantopithecus among the hominids in terms of reclassifying previously puzzling data, I think it inappropriate and counter-productive to exceed the data and the scholarly discussion it has generated.

Cronin (1975), in his article discussing the unknown hominid (Yeti?) which walked around his tent in the Arun Valley of Nepal on the night of December 19, 1972, suggests that Gigantopithecus may have been crested. I hope it is obvious that in principle I agree with the relative likelihood of that supposition. I point out, however, that A. robustus is known to have been crested, and his remains in Africa and Java place him in a range the middle of which is the Himalayas. I have the same difficulty with Bourne's and Krantz's repeated suggestions that if Bigfoot is real, then Gigantopithecus represents a good potential ancestor.

I respond to Porshnev (1974) and Bayanov and Bourtsev (1976) regarding Homo neanderthalensis as a viable alternative in my "More on Neanderthal vs. Paranthropus" (Strasenburgh 1979).

The Basic Problem
The present position of the anthropological community in North America appears to be that until "concrete" evidence is forthcoming, scientific attention cannot be properly turned to Bigfoot. T. Dale Stewart, for example, observed in "MONSTERS! Mysteries or Myths?"

Eyewitness testimony in the case of Bigfoot I don't think is very good because you can't test it. It's credibility of the person and these people...they want to see something strange, they can imagine it. I don't believe in Bigfoot because no hard evidence has been presented. Ail the evidence so far is in the form of footprints and such reports--all of which constitute soft evidence...Hard evidence is like [a] skull [emphasis in original].

Any uncertainty apparently categorically precludes investigation and discussion of the subject. As I have pointed out (Strasenburgh 1975), this preoccupation with the need for a specimen tends to obscure the fact that a significant number of 19th and 20th century North Americans have testified to encounters with the species. Sasquatch is therefore, at least, a remarkable survival of-the Wildman myth (Bayanov and Bourtsev 1976; Bernheimer 1970; Kirtley 1964; Strasenburgh 1975; Vlcek 1960).

If this is the extent of the Sasquatch phenomenon, the anthropological community can neither acknowledge it nor comment on it so long as it persists in demanding a specimen. If one grants the possibility that Sasquatch is a real rather than mythological hominid species, then the current North American anthropological position Sasquatch any calculation of the probability that such might be the case. The key to the dilemma that Sasquatch increasingly poses for the North American anthropological community, short of a specimen, is the examination of the best data.

Accounts of encounters and the consistent descriptions which accompany them can be of no use until the demand for concrete evidence is tempered and this facet of the phenomenon is validated. In the present circumstances, the layman's documentation of it (Green 1973a, 1973b; Hunter and Dahinden 1973; Porshnev 1968; Sanderson 1961; Tchernine 1971), while impressive, is not the best datum.

The collected footprint casts that have been examined by Napier (1972) and Krantz (1972) represent a higher, but still imperfect, grade of datum. Against the published positions of these two scientists that the footprint casts represent good, positive data, there appears to exist a widely accepted opinion that footprint casts are liable to undetectable fabrication. Since the judgment of footprints is more the forte of native guides than of western urban man in general or physical anthropologists in particular, such suspicion is accountable. I think it unfortunate, however, that North American anthropology has thus far responded to Krantz and Napier's analyses and conclusions with unpublished rebuttal. But however good the analyses and data of the footprint casts may be, they are not the best data.

The Patterson-Gimlin film and its analytical results to date are the best data. The film offers many advantages that the footprint casts cannot. Its exposure date is known with certainty. It is frozen in time, and may be examined in the context of a future now equal to a decade. The location of the filming is known with certainty, and can be further plotted to quantify the movement of the subject and the camera during the sequence, as well as the dimensions of the image. The existence of several copies of the film offers the opportunity to check for any tampering since it was exposed and developed. The film may be duplicated/with ease and accuracy.

Most importantly, the film represents a well-understood and accepted form of datum to biomechanics. Judging from the published record of analyses, anthropology has a willing partner in the undertaking. And one that is uniquely qualified to reach an authoritative judgment on the authenticity of the film from a non-anthropological point of view.

For all of the above reasons a thorough and impartial biomechanical and anthropological analysis of the Patterson-Gimlin film by the North American anthropological community would appear appropriate. I would hope that such an analysis would include a comparison between the locomotor pattern of the Patterson-Gimlin film image and those hypothesized for the other hominid.

References Cited

Aguirre, Emilliano
1974, Comments: The Troglodytidae and the Hominidae in the Taxonomy and Evolution of Higher Primates by Boris F. Porshnev. Current Anthropology 15 (4):450.

Bayanov, Dmitri, and Igor Bourtsev
1976. On Neanderthal vs. Paranthropus. Current Anthropology
17 (2):312-318.

Bernheimer, Richard
1970. Wild Men in the Middle Ages. New York: Octagon Books. Cronin, Edward W., Jr.
1975. The Yeti. The Atlantic Monthly:47-53. November.

Green, John
1973a. On the Track of the Sasquatch. New York: Ballantine Books.
1973b. The Sasquatch File. Agassiz, B.C.: Cheam Publishing.

Hunter, Don, with René Dahinden
1973. Sasquatch. Toronto: McClelland and Stewart.

Jolly, Clifford J.
1970. The Seedeaters: A New Model of Hominid Differentiation
Based On a Baboon Analogy. Man. New Series 5 (1):5-26.

Kirtley, Bacil F.1964 Unknown Hominids and New World Myths. WesternFolklore 23:77-90.

Krantz, Grover S. Anatomy of the Sasquatch Foot. Northwest Anthropological Research Notes 6 (1):91-104.
1972b. Additional Notes on Sasquatch Foot Anatomy. Northwest Anthropological Research Notes 6 (2):230-241.

Morris, Desmond The Naked Ape. New York: McGraw Hill.

Napier, John R.Bigfoot. London: Jonathan Cape.

Poirier, Frank E.
Comments On The Troglodytidae and the Hominidae In the Taxonomy and Evolution of Higher Primates by Boris F. Porshnev. Current Anthropology 15 (4):449-450.

Porshnev, Boris F.
1960. The Struggle for Troglodytes (in Russian). Prostor 4, 5, 6, and 7. Moscow.
1974. The Troglodytidae and the Hominidae in the Taxonomy and Evolution of Higher Primates. Current Anthropology15 (4):449-450.

Robinson, John T.
1956. The Dentition of the Australopithecinae. Transvaal Museum Memoires No. 9.
1972. Early Hominid Posture and Locomotion. Chicago: The University of Chicago Press.

Sanderson, Ivan T. 1961. Abominable Snowman: Legend Come to Life. Philadelphia: Chilton.

Strasenburgh, Gordon
1975. Perceptions and Images of the Wild Man. Northwest' Anthropological Research Notes 9 (2):281-298.
1979. More on Neanderthal vs. Paranthropus. Current Anthropology 20 (3):624-627.

Tchernine, Odette 1971. In Pursuit of the Abominable Snowman. New York: Taplinger.v

Vlcek, Emanuel
1960. Diagnosis of the "Wild Man" According to Buddhist Literary Sources From Tibet, Mongolia, and China. Man 60(10):153-154.

© Gordon Strasenburgh

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