In the common conception of theoretical and observational statements in science, that of Rudolf Carnap, theories can only be confirmed by predicting future observations accurately, while observational statements contain empirical (and presumably completely common) terms.(1) This assumes a distinction between observable and nonobservables - any statement that contains an non-observation term is a theoretical statement. This model is brought into question, however, if, as N. R. Hanson implies, observation itself is theory-laden.(2) It seems obvious in certain cases, such as the dispute over the sex life of the whiptail lizard, that when the same physical events are observed by different people bringing different assumptions into the situation, what is "observed" can vary radically. When one scientist, David Crews, observed the non-sexual animals in question, based in the cross-discipline nature of his field, he believed that what he was observing was mating behavior and formulated his theories based on those observations. Rather than calling into question the theory derived from what Crews observed, others in the field who had worked with the animals before attacked his observations themselves as unnecessarily presumptuous. These scientists had observed the same behavior, and had merely seen trivial side-effects of captivity common to many animals rather than anything sexual and thus notable. Both in the dispute seemed to have seen the same act, and yet each observed something different. This dispute clearly supports Hanson's argument, as it was ultimately never resolved -- the supposedly common factor in a theoretical dispute, the empirical nature of an observation, was itself the point of contention.

David Crews brought to his study of the lizards a history studying both zoology and psychology in reptiles. Instead of studying either the reproductive systems and sexual behaviors of his subjects like a neuroendocrinologist, or the natural history of them like herpetologists, Crews studies the evolution of the systems in their bodies by examining their physiology and observing their behavior. Cnemidophorus uniparens is a thoroughly interesting specimen in terms of the evolution of sex, as it reproduces parthogenetically and internally, producing an endless line of females that need no male fertilization of their eggs (and thus have no complicating male factor in their lineage).(3) Even more strikingly, some other types of whiptails (such as the western American Cnemidophorus tigris multiscutatus) are sexual lizards with both males and females.(4) All of this makes the nonsexual nature of C. uniparens very important to the evolution of sex in other species, especially in Crews's particular area of study, where the difference in behavior between sexual and nonsexual theories may prove or refute long-standing theories of sexual explanation for behavior.

What Crews observed the lizards doing, though, he found to be both quite clear and quite shocking. He witnessed captive specimens of C. uniparens mounting each other, twisting their bodies together, in seemingly fruitless embraces. This, to Crews, an expert on the sexual behavior of lizards, was obviously the mating behavior of sexual whiptails, manifesting itself in a nonsexual species. To him and his coworker Fitzgerald, this was obvious; to look at the lizards was to observe mating behavior.(5) Crews proposed theories as to the nature of this behavior after dissecting both the 'top' and 'bottom' lizards. The one mounting, he observed, had ovaries in a stage of reproductive inactivity, while the one mounted had fully fertile, preovulatory follicles. Thus, the sexual behavior might well not just be a remnant of behavior from an evolutionary ancestor -- it might be involved in the lizards' nonsexual reproduction as a sort of pseudo-copulation that prepared the lizard playing the 'female' role for egg production. For Crews and Fitzgerald, the sexual aspect of the lizards' actions was part of the observation and empirical data gained; what they saw, from their ample previous experience with lizard copulation, was certainly a 'false' form of such behavior. The only thing that remained was to start proposing and testing theories as to why this behavior occurred which might provide further predictions for observation (thus confirming or refuting their theory about the need for pseudocopulation in the production of eggs) and thus gain a useful tool in their own field.

Needless to say, in the United States and elsewhere, Crews's theories remain a sensational bit of popular science trivia -- the appeal of "lesbian lizards" seems too big to be quashed by real scientific dispute, most likely in part because of the political and ethical dispute over homosexual behavior among humans that often revolves around what is and is not "natural". Nerve, a popular periodical on the subject of (human) sex, even published an article about the lizards in 2000 where the author focused exclusively on the novelty of Crews's theories and his work with the lizards without mentioning any scientific dispute over them at all.(6) But the dispute is real, continues to this day, and began when other scientists questioned not the reproductive function of the observed pseudocopulation, but the observations themselves.

Long before Crews appeared on the scene, the fascinatingly parthogenetic C. uniparens had its own established experts in the field of herpetology, none of whom had published theories referring to this pseudocopulation and its role in reproduction. Crews was admittedly a challenge to their authority if they had overlooked so vital a behavior, but important people in the study of the species, like C.J. Cole and Orlando Cueller, attacked the very nature of what Crews had observed.(7) The activity, they said, was not copulation at all, and had no sexual nature. They themselves had observed the lizards mounting each other (albeit, they said, only a tiny minority in peculiar circumstances). As experienced researchers, they claimed, they would have known and noted pseudocopulatory behavior if they had seen it. What they saw was merely nonstandard activity, which could most likely be explained not by theories about its role in the lizards' reproduction but as isolated artefacts resulting from human interaction with the lizards -- namely, their captivity. A truly experienced observer would not have lifted an eyebrow.

Crews and Fitzgerald were offering, in these experts' eyes, theory-laden observations: rather than simply presenting the behavior as-is in empirical terms, the two had unnecessarily brought the biases of their sex-oriented research into play and assumed (wrongly) that what they were seeing was sexual behavior. Yet, Crews thought that what he was seeing was properly described as copulation (based on his own past empirical experience with sexually reproducing lizards he knew to be mating) - he could look at the lizards and describe what he saw as 'copulation', and it was not a matter of dispute that this behavior in other lizards was that act. The element of interpretation only came into play in the theoretical nature of this behavior's cause. Crews cleverly turned his critics' claims about their observation against them, questioning their relative fitness as researchers who managed not to observe the behavior that was so obviously present.(8) Crews asserted that claims by the other researchers that they had seen such behavior many times in the past actually provided support for his observations (and, he implied, proved that he was better equipped to research this behavior than them because of their inability to see what it actually meant). The argument was from the beginning one not of theory but of observation - what Crews saw, against what Cole and Cuellar saw.

But wait a minute -- wasn't part of Cole and Cuellar's arguments that they saw the exact same thing as Crews? Why was this observed as 'copulation' by Crews but as 'artefact' by earlier researchers, when empirical observations are supposed to be the hard and fast way to verify disputed theories? Shouldn't both sides, by this point, know what copulation in whiptails looks like? Views advanced by N. R. Hanson in Observation (1958) would tend to agree with Cole and Cuellar's assessment of Crews and Fitzgerald's observations as theory-laden, but would not fault them for this -- because to Hanson, conceptual organizations brought into any given observation will change, on some level, what each observer 'sees'. Hanson gives the explicit example of possible artefacts in another field, that of microbiology, where one scientist sees a cell organ in a slide under observation, while another sees only a human error in the staining technique.(9) Obviously, the two scientists are probably not getting different images on their retinas or exhibiting neurophysiological differences in themselves, whether they be observing a curious body on a slide or a curious behavior among captive lizards. Yet, to say that they are "interpreting" what they see when they offer their observations is problematic, because all Crews had to do was see what the lizards were doing to identify copulation -- seemingly not applying any nonobservables at all, but rather the observational terms of his own previous empirical experience. "Instantaneous interpretation hails from the Limbo that produced unsensed sensibilia. . . these are ideas which philosophers force on the world to preserve some pet epistemological or metaphysical theory."(10)

While the dispute between Crews and Cole moved into questioning professional practices, such as the way in which Crews treated his captive lizards or Cole's failure to keep detailed data on the same, the basic argument remains not over these possible causes but the observation itself. It may, in fact, be true that Cole and Crews saw the same behavior among the C. uniparens specimens they observed; it may also be true that on another level, where Crews saw copulation, Cole saw no such thing. This does not necessarily invite radical relativism to the table -- it simply acknowledges that the conceptual organization of the viewer is contained within the observation in question, and that simply pointing to empirical evidence is no way of providing a perfectly common ground from which to work. Hanson gives the excellent example of Kepler and Tycho observing the morning sky in the east(11) -- they both see a flaming upside-down two-dimensional disc on their retinas, flipped right-side-up by their brains; they also both see a three-dimensional celestial body known as the sun. But to Kepler, it is stationary, while to Tycho, it is moving around the earth, something that they both claim to 'see' as it rises, the same way that different researchers in this dispute 'saw' different behavior. Crews and Cole's disputes reinforce that for anyone to be able to use 'the same' observations in a different fashion, those observations must in some way actually be different.

The dispute over pseudocopulation in the whiptail lizard rages on, no doubt in part to the basically philosophical nature of the disagreement over empirical observation. When theories and nonobservables are called into question, it seems that less is personally at stake for the scientist being criticized; he or she may be guilty of ad hoc or faulty reasoning, but at least the scientist's necessary professional ability to make accurate observations is not felt to be under review. Both sides can use the complicated reality of what seeing and observation actually are to undermine their rivals, claiming that opposing observations are slipshod, indicate professional ignorance or incompetence regarding the object of the observations, or are built on unnecessary assumptions. In truth, both must admit and undertake a radical reevaluation of how they view the issue; they must consider that all of their observations are, in fact, the partial product of their theories.

(1) Carnap, 1966.

(2) Hanson, 1958.

(3) Collins, H. M. and Trevor Pinch. The Golem: What You Should Know About Science. Cambridge University Press, Cambridge, 2nd ed. 1998. p 111.

(4) USGS Western Ecological Research Station Field Guide. .

(5) Collins, p 113.

(6) .

(7) Collins, p 113.

(8) Collins, p 115.

(9) Introductory Readings in the Philosophy of Science. Ed. E.D. Klemke, Robert Hollinger, David Wyss Rudge. Prometheus Books, Amherst, 1998. "Observation", by N.R. Hanson (pp 339-351). p 339.

(10) Hanson, p 344.

(11) Hanson, p. 341.

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