Role of science

When we talk about “science tells us” and so on, sometimes it’s good to reflect on the abstraction of “science” and what makes any human activity “science.”
Dan Sarewitz looked at a couple of different perspectives, from theoretical physics to improving antifreeze formulations in this piece..

What, then, joins Hossenfelder’s field of theoretical physics to ecology, epidemiology, cultural anthropology, cognitive psychology, biochemistry, macroeconomics, computer science, and geology? Why do they all get to be called science? Certainly it is not similarity of method. The methods used to search for the subatomic components of the universe have nothing at all in common with the field geology methods in which I was trained in graduate school. Nor is something as apparently obvious as a commitment to empiricism a part of every scientific field. Many areas of theory development, in disciplines as disparate as physics and economics, have little contact with actual facts, while other fields now considered outside of science, such as history and textual analysis, are inherently empirical. Philosophers have pretty much given up on resolving what they call the “demarcation problem,” the search for definitive criteria to separate science from nonscience; maybe the best that can be hoped for is what John Dupré, invoking Wittgenstein, has called a “family resemblance” among fields we consider scientific. But scientists themselves haven’t given up on assuming that there is a single thing called “science” that the rest of the world should recognize as such.

The demarcation problem matters because the separation of science from nonscience is also a separation of those who are granted legitimacy to make claims about what is true in the world from the rest of us Philistines, pundits, provocateurs, and just plain folks. In a time when expertise and science are supposedly under attack, some convincing way to make this distinction would seem to be of value. Yet Hossenfelder’s jaunt through the world of theoretical physics explicitly raises the question of whether the activities of thousands of physicists should actually count as “science.” And if not, then what in tarnation are they doing?

When Hossenfelder writes about “science” or the “scientific method” she seems to have in mind a reasoning process wherein theories are formulated to extend or modify our understanding of the world and those theories in turn generate hypotheses that can be subjected to experimental or observational confirmation—what philosophers call “hypothetico-deductive” reasoning. This view is sensible, but it is also a mighty weak standard to live up to. Pretty much any decision is a bet on logical inferences about the consequences of an intended action (a hypothesis) based on beliefs about how the world works (theories). We develop guiding theories (prayer is good for you; rotate your tires) and test their consequences through our daily behavior—but we don’t call that science. We can tighten up Hossenfelder’s apparent definition a bit by stipulating that hypothesis-testing needs to be systematic, observations carefully calibrated, and experiments adequately controlled. But this has the opposite problem: It excludes a lot of activity that everyone agrees is science, such as Darwin’s development of the theory of natural selection, and economic modeling based on idealized assumptions like perfect information flow and utility-maximizing human decisions.

Of course the standard explanation of the difficulties with theoretical physics would simply be that science advances by failing, that it is self-correcting over time, and that all this flailing about is just what has to happen when you’re trying to understand something hard. Some version of this sort of failing-forward story is what Hossenfelder hears from many of her colleagues. But if all this activity is just self-correction in action, then why not call alchemy, astrology, phrenology, eugenics, and scientific socialism science as well, because in their time, each was pursued with sincere conviction by scientists who believed they were advancing reliable knowledge about the world? On what basis should we say that the findings of science at any given time really do bear a useful correspondence to reality? When is it okay to trust what scientists say? Should I believe in susy or not? The popularity of general-audience books about fundamental physics and cosmology has long baffled me. When, say, Brian Greene, in his 1999 bestseller The Elegant Universe, writes of susy that “Since supersymmetry ensures that bosons and fermions occur in pairs, substantial cancellations occur from the outset—cancellations that significantly calm some of the frenzied quantum effects,” should I believe that? Given that (despite my Ph.D. in a different field of science) I don’t have a prayer of understanding the math behind susy, what does it even mean to “believe” such a statement? How would it be any different from “believing” Genesis or Jabberwocky? Hossenfelder doesn’t seem so far from this perspective. “I don’t see a big difference between believing nature is beautiful and believing God is kind.”

Every time I think public lands issues are contentious, I just look at my climate science newsfeeds and thank Gaia for our community! But I think for those of us who haven’t been up close and personal with the science biz,it’s important to to understand some of the debates about advocacy vs. objectivity and how that plays out. It’s kind of funny sometimes being an Old Person. I remember when I was a “Population Geneticist”. Somewhere along the lines, after I graduated with my Ph.D., some of my colleagues started calling themselves “Conservation Geneticists.” During a discussion, one of these colleagues called me an “Exploitation Geneticist” ;). If you didn’t live through this yourselves, trust me that there was a time when scientists were supposed to be objective and fair as possible. That ship has sailed. I will leave it to you to decide whether that is a good thing or not. As for me, I think you have to “pick a lane” either scientific information tries to be objective, or it is a tool in support of advocacy. Anyway, enough history from this Older Person. Here’s a link to a piece by Keith Kloor in Issues in Science and Technology.

In 2013, Canadian ecologist Mark Vellend submitted a paper to the journal Nature that made the first peer reviewer uneasy. “I can appreciate counter-intuitive findings that are contrary to common assumption,” the comment began. But the “large policy implications” of the paper and how it might be interpreted in the media raised the bar for acceptance, the reviewer argued.

Vellend’s finding, drawn from a large meta-analysis, challenged a core tenet of conservation biology. For decades, ecologists have held that the accelerated global rate of species extinctions—known as the biodiversity crisis—filtered down to local and regional landscapes. This belief was reinforced by dozens of experimental studies that showed ecosystem function diminished when plant diversity declined. Thus a “common assumption” was baked into a larger, widely accepted conservation biology narrative: urbanization and agriculture, among other aspects of modern society, severely fragmented wild habitat, which, in turn, reduced ecological diversity and eroded ecosystem health.

And it happens to be a true story—just not the whole story, according to the analysis Vellend and his collaborators submitted to Nature. In actuality, plant diversity at localized levels had not declined, they found. To be sure, in landscapes people had exploited (for example, for agriculture or logging), habitat became fragmented and nonnative species invaded. But there was no net loss of diversity in these remnant habitats, according to the study. Why? Because as some native species dropped out, newer ones arrived. In fact, in many places, species richness had increased.

The peer reviewer did not hide his dismay:

Unfortunately, while the authors are careful to state that they are discussing biodiversity changes at local scales, and to explain why this is relevant to the scientific community, clearly media reporting on these results are going to skim right over that and report that biological diversity is not declining if this paper were to be published in Nature. I do not think this conclusion would be justified, and I think it is important not to pave the way for that conclusion to be reached by the public.

Nature rejected the paper.

Although it was published soon after by the Proceedings of the National Academy of Sciences—without triggering media fanfare, much less public confusion—the episode unsettled Vellend, who is an ecology professor at the University of Sherbrooke, in Quebec. His uneasiness was reinforced when he presented the paper at an ecology conference and several colleagues voiced the same objections as the Nature reviewer.

Vellend discusses all this in an essay that is part of a collection titled Effective Conservation Science: Data Not Dogma, to be published by Oxford University Press in late 2017. His experiences have left him wondering if other ecology studies are being similarly judged on “how the results align with conventional wisdom or political priorities.”

The short answer appears to be yes.

Warning: the rest of the article includes climate science drama.