What Ardi Reveals About the Syntax of Scientific Findings

Big in the news right now is Ardi — the oldest known hominid skeleton (see the news here). This finding is thought to cast new light on early ancestors to humans and the upright origins of humankind. Without getting into a discussion on evolution I would like to use Ardi as a case study in scientific syntax. My wife is a chemist. She has often said that reporting research involves a great deal of massaging the syntax. How things are worded is important in reporting scientific findings. If things are not worded correctly findings can be overstated or understated. For example, if evidence e shows hypothesis h is probable one would not want to say that the evidence is conclusive in support of the hypothesis (unless the probability surpasses some threshold of conclusivness pre-established or generally understood by that scientific community). Scientific syntax needs to be properly hedged — words need to be properly chosen and arranged — to communicate semantics that are true to the findings. Syntax can even, dare I say, be used to get the findings to say things the evidence does not support.

Below are some quotes from the scientific findings as reported by the scientists in the magazine Science (2 October 2009 Vol. 326). I will place quotation marks around syntax of interest and briefly comment on the quote.

Despite its small cranial capacity, there is “tantalizing evidence” for advanced cranial based flexion in Ar. ramidus. (68e6)

It is interesting that an emotive word like “tantalizing” was used. Here is another quote that utilized a similar emotive word (“anxiously”).

More fossils willfurther advance our understanding of the CLCA, and we “anxiously await” their discovery. (74e7)

The emotive word choice makes the authors seem like they are excited about receiving more fossils, which “will” advance their understanding. There is a presumption in favor of evidence fitting theory and that what is found “will” bolster understanding. A critic might wonder whether there is some “making evidence fit theory” going on.

Now I will highlight the use of hedging in reporting scientific findings.

One of the instructive aspects of adaptive suites is the demonstration of what “must almost always” be a complex network of character interactions, even in reptiles and amphibians. “More often than not“, such interconnectivity is “likely to far exceed” relatively simplistic arguments such as somatic budgeting. (74e7)

What does “must almost always” mean? Is this like Brian Fantana in the movie Anchorman remarking about the effectiveness of Sex Panther cologne: “60% of the time, it works every time”? Also, what does more often than not” interconnectivity is likely to far exceed” mean? Does this mean greater than 50% of the time interconnectivity is “probably” going to outperform somatic budgeting. It is difficult to see what this hedging amounts to. Other classic hedging syntax includes: the records “suggest” X, it is now “equally clear” that Y, our comparative analyses of P “suggests” that this “probably” reflects Z. It is hard to track double-qualifications of likelihood and once identified it makes me wonder how much of the syntax is smoke-and-mirror methodology (i.e., purposely not showing one’s full cards). Another possibility is the double-hedging indicates lack of certainty on behalf of the scientists. This is more often than not probably what is going on (lol). Interpreting these findings over a period of years will determine what the findings really mean. It is ultimately the consensus of the scientific community that will settle the meaning of the evidence for various hypotheses about evolution.

Another thing that is clear from looking at the syntax of the Ardi findings is that a great deal of inferences occur in unearthing the fossils, putting together the skeleton, revising the skeleton until the scientists are happy with the reconstruction, building digital reconstructions of the entire skull, pelvis, and limbs to fill in the gaps and generate a fleshed-out virtual model and then from this virtual model drawing inferences about what hypotheses the evidence supports. For example:

The “digitally reconstructed” [Ardi] skull further allows “a variety of inferences” about African ape and hominid evolution. Cranial capacity…was “probably slightly smaller” than….The [Ardi] skull lacked the masticatory specializations of later Australopithecus, consistent with the dental evidence for an omnivore/frugivore niche lacking emphasis on hard and/or abrasive diets. Finally, comparisons of [Ardi] and extant African apes “suggest” that each is unique in aspects of its cranial anatomy. (68e6)

It would be interesting to calculate the probability of the inferences reported in the research. From the evidence the scientists infer that certain conclusions are correct or that certain hypotheses are confirmed. Many of the inferences are based on digital reconstructions. How accurate are the digital models? How likely are the models to reflect the actual creature? Is Ardi representative of that genus of animals? The sample size is so small that it makes me wonder if it is possible to infer from Ardi a conclusion about skull size in relation to Lucy (Australopithecus), especially because the sample size is so small in both cases. In my estimation the probability of these inferences from the evidence is mitigated by so many factors that the probability must be “reported” as small if the findings are to match the probability of the hypotheses conditional on the evidence. However, maybe I’m just playing with the syntax.

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  1. Though I did not mention this in the original post, another dimension of interpretation involves mainstream media. What scientists report tentatively the mainstream media interprets even further. This leads to inferences that are not properly qualified. The result is that people take what they read from mainstream media outlets as fact. In the Ardi case the conclusions are super-hedged by the scientists and the implications of the findings tentatively asserted. Mainstream outlets infer from these hedged inferences and drop the important probabilistic qualifications. The result is that the mainstream media inferences appear highly probable or likely to be scientific fact. As an example of mainstream media interpretation of Ardi, the quote below was pulled from a commentary in Forbes magazine by Lionel Tiger. The last paragraph is a salient expression of my point.

    “This moral coding of behavior has already begun, if tentatively and with much throat clearing. For example, there is useful attention paid to the reduction in the size of upper teeth–the sharp fang-like instruments for aggression and defense. A possible explanation given for this is that teeth in Ardi’s clan were no longer as important for male-male combat as in other fossilized and contemporary primates. And going on from there, it is suggested that Ardipithecus was less socially aggressive than the living chimpanzees we thought were our closest relatives, and other African apes. In addition, the canine teeth of males and females are relatively similar in size–in contrast to those of African apes, among whom male teeth are larger–and this suggested to the team of researchers that Ardi lived in a social system with less male-male competition than in other species.

    Not only does this imply that Ardi males were morally more acceptable to contemporary values than other species, but it is suggested that an important possible outcome of the greater male-male conviviality could well have been greater male emphasis on their work as fathers.”

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