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PLoS Biology recently published an essay by Brooke Smith and colleagues, focused on "Navigating the rules of scientific engagement" [1]. The authors represent COMPASS, a nonprofit organization dedicated to bringing the knowledge of ocean scientists to greater public awareness and influence in public policy decisions. The essay includes some insightful themes on bringing more effective modes of public engagement into scientific research. The essay is open access and under a Creative Commons license, so I'll excerpt a few passages I think are especially worthwhile.

To begin with, the essay explains why engagement is a key concept in science communication:

Science communication was once considered primarily a unidirectional conveyance of information, based on the assumption that if scientists and other experts could convey their knowledge to the public, typically through “data dumps," society's problems could be solved (i.e., if you knew what I know, you would believe what I believe). This perspective, “the science deficit model of the public", is explored in a body of communications literature [6]–[8]. We know it does not work [9].

Communications is not only about speaking in a clear, compelling, and relevant manner, nor simply about promoting findings. Effective communications is an integrated process of understanding your audience and connecting with that audience on their terms. It requires listening as well as talking.

As practitioners within the evolving field of science communication, we've also adapted our approach to one that facilitates dialogue and encourages engagement. We've learned that if scientists want to have impact beyond their disciplines and in the world, communications must be central to their enterprise [10]. This is why academia should reconsider its measures of success and make communication training an integral part of graduate-level education.

The "deficit model" is the naive assumption made by many scientists, who may believe that the reason why the public misunderstands scientific concepts is that people just haven't spent time learning the correct explanations. Of course, the public is heterogeneous and some people will be receptive to a simple explication of a scientific finding or principle. But in well-entrenched areas of misunderstanding of science, the deficit model is rarely an accurate picture. Talking "at" people is very likely to increase their resistance to scientific reasoning, precisely because it shows the scientists themselves to be unreasonable. As the essay discusses, listening and responding sincerely to an audience's concerns and questions are fundamental parts of engagement.

The essay approaches the issue of "science by press release" with a heterodox viewpoint: Getting broad public attention for a controversial finding may in some cases help scientific progress, if the researchers are prepared to make productive use of critical commentary.

We remind the authors that making a splash in the mainstream press tends to incite controversy, whether over the science itself, the communication of it, or both. Backlash is never pleasant, but it is not necessarily negative [5]. In our experience, when the science is robust, and authors are committed to the questions instead of the results, criticism can catalyze productive collaborations and push the field forward.

The authors include an example along these lines, in which a controversial research result led to the creation of a collaborative group that broadened the scope and public application of the line of research.

This is a valuable insight:

Scientists who can clearly explain a research finding and why it matters are poised to succeed not just in outreach, but also in grant writing, interdisciplinary collaborations, teaching, and other essential roles. Being a good communicator is not a tradeoff; it is a key component of scientific success. Like most other elements of a strong academic career, it's a skill that may be rooted in natural talent and personal interest, but can always be further developed by training, preparation, and practice.

We work on making our students good communicators in many ways -- from encouraging them to present their research to the public, school groups, at professional meetings, and in the university. Part of this strategy of multilevel communication is to enable students to discuss their work effectively at different lengths -- from the "elevator talk" to a full research presentation.

But the COMPASS essay suggests to me that "listening" skills also need to be part of our training. I have learned over time the value of having many different ways to describe my research, so that I can deploy the most relevant and topical information to the person I'm meeting. Being able to do quickly switch contexts requires an ability to ask questions of other people, out of genuine interest in what they bring to the conversation. That is engagement.

References

An interesting essay in the New York Times today by Jo Robinson: "Breeding the Nutrition Out of Our Food". The theme is that plant domestication selected for certain traits that made our grains and vegetables more amenable to rapid calorie production, but these have often decreased the amounts of micronutrients in the resulting food products:

Studies published within the past 15 years show that much of our produce is relatively low in phytonutrients, which are the compounds with the potential to reduce the risk of four of our modern scourges: cancer, cardiovascular disease, diabetes and dementia. The loss of these beneficial nutrients did not begin 50 or 100 years ago, as many assume. Unwittingly, we have been stripping phytonutrients from our diet since we stopped foraging for wild plants some 10,000 years ago and became farmers.

These insights have been made possible by new technology that has allowed researchers to compare the phytonutrient content of wild plants with the produce in our supermarkets. The results are startling.

I think it's useful to keep in mind that the qualities of food that loom important for us now, in an age of rapid transcontinental refrigerated food transportation, are not the same qualities that mattered to the first agriculturalists. Five thousand years ago, people needed food products that could be stored through the lean season, that made harvesting the plants easier, and that resisted the insults of bad weather and pathogens. Robinson focuses attention on the developments of the last hundred years, in which some crop varieties have been selected for much higher sugar content, but the long history of domestication before these recent events has also shaped the taste and nutrient content of foods.

I also demur from the conclusion about the health of ancient people:

Were the people who foraged for these wild foods healthier than we are today? They did not live nearly as long as we do, but growing evidence suggests that they were much less likely to die from degenerative diseases, even the minority who lived 70 years and more. The primary cause of death for most adults, according to anthropologists, was injury and infections.

I wouldn't generalize on this point, which would be tricky to demonstrate given the evidence we have. My inclination is exactly the opposite of Robinson's implication here: the minority of hunter-gatherers who live to advanced ages are relatively healthy because the slightly less healthy ones at all life stages are more likely to be felled by infections and injury. This is the concept of "frailty" in life history theory, and is well demonstrated in some historical famines and epidemics. The people who are least healthy are least likely to survive. What we have today is an advanced ability to allow relatively unhealthy people to survive to advanced ages despite their health problems.

Still, I think the essay's bottom line is basically correct. More diversity of foods is better. Selecting foods as part of your diet that have come from a broader array of heirloom and wild varieties is one way to add to that diversity.

Last week, Nature published a paper by Christine Austin and colleagues, in which they developed a new approach to understand how breastfeeding affects the elemental content of tooth enamel [1]. Barium and strontium are chemically similar to calcium (all three are in the same column of the periodic table of elements), and a small fraction of both elements are incorporated into enamel and dentine in place of calcium. The fractions of barium and strontium incorporated in teeth depend on an individual's diet; different food sources have different concentrations of these elements. So the concentrations of these elements in tooth enamel give some indication of the diet sources that an individual relied upon when her teeth were developing.

Two of the most significant diet changes occur early in life -- the change at birth when an infant begins relying upon mother's milk, and the change at weaning from milk to other kinds of foods. Austin and colleagues set out to examine whether they could reliably determine the timing of these two transitions, based upon knowledge of the enamel deposition process:

We propose that micro-spatial analysis of barium/calcium ratios (Ba/Ca) in dental tissues represents a powerful approach to assess dietary transitions. Whereas prenatal Ba transfer is restricted by the placenta, marked enrichment occurs immediately after birth from mother’s milk or infant formulas, which contain higher Ba levels than umbilical cord sera. In response to these variations in dietary Ba exposure, Ba/Ca in enamel and dentine should increase at birth, remain elevated for the duration of exclusive breastfeeding and rise further with introduction of infant formula. Circulating Ba levels are expected to change at weaning as Ba (and Ca) content and bioavailability is markedly different across plant and animal food sources. To test this hypothesis, we investigated Ba/Ca patterns in teeth from human children for whom early life diets were recorded prospectively, and in teeth from captive macaques in which maternal milk was collected and suckling behaviour observed.

They applied their method to deciduous teeth that came from children whose mothers had participated in the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) study in Monterey County, California. This allowed Austin and colleagues to examine the fraction of barium in enamel and dentin, layer by layer, within children whose diets had been recorded including the dates of exclusive breastfeeding, supplemented breastfeeding, transition to infant formula and full weaning. The sample of teeth is not very large (only 25 individuals) but the barium signals within the teeth tracked very well with the dates reported for birth, breastfeeding and transition off milk. Additionally, Austin and colleagues considered the teeth of four macaques whose record of suckling and weaning had been recorded. The macaques did not have the confounding influence of formula supplementation, and their barium/calcium signatures gave quite clear records of natural, gradual weaning versus abrupt weaning upon the separation of mother and juvenile.

Although both barium and strontium may provide a signal of these diet changes, Austin and colleagues focused on barium because strontium is more likely to be shifted within ancient tooth enamel after it has been buried in the ground. The goal of the paper was not only to show that the signature of breast feeding is consistent within living populations (in this case, macaques and humans) but also to provide a way to infer these dietary transitions in ancient primates. To that end, they examined the pattern within a Neandertal tooth from Scladina, Belgium:

Chemical and temporal mapping of Neanderthal first molar enamel (Fig. 3) revealed a transition pattern similar to the macaque that weaned abruptly. After approximately 13 days of prenatal enamel formation, Ba/Ca near the enamel–dentine junction increased and remained elevated until approximately 227 days of age (~7.5 months), followed by intermediate values until 435 days of age (1.2 years). After this age Ba/Ca rapidly returned to prenatal levels for the final 1.15 years of crown formation.

They infer that the Neandertal child was moved off exclusive breastfeeding to partial supplemented breastfeeding at around 7.5 months of age, which the authors suggest is consistent with the pattern in other primates. Then, they suggest that the extended period of breastfeeding in conjunction with solid food supplementation was "abruptly" cut off at the unusually low 1.2 years. After that time, the child continued to grow, apparently without mother's milk.

Katie Hinde, one of the authors of the research paper, has written a blog post giving a lucid explanation of the research and its background: "Teeth and Weaning and Neanderthal… OH MY!" She discusses whether the Scladina tooth is sufficient to make inferences about Neandertal life history more generally:

So do we think we know the species typical pattern of Neanderthal weaning? Not at all. The precipitous decrease of barium at 1.2 years of age pretty clearly suggests that the Scladina Neanderthal was abruptly weaned in a non-typical fashion.

...

We have a really powerful way to investigate the period of exclusive milk feeding and the weaning process with high precision and resolution. For the first time we have a method to look at individual differences in these parameters in primates “collected” by old school naturalists gathering dust in natural history museums or skeletal material recovered at primate field sites. And we can do this in well-preserved fossil hominins... if colleagues are willing to share.

I think this research is really great, and I was talking about it the other day as an example of how we are uncovering evidence about ancient people that was previously invisible to us. Obviously, I'd like to see the same kind of analysis extended to much larger samples of teeth. This paper is a very promising start to the research, but we need to understand what variation there may be within living humans who are eating a broader range of diets, and who may have somewhat different patterns of tooth development.

What I think is most encouraging about this line of research is that breastfeeding may give a natural chemical tracer that will allow researchers to confirm the periodicity of enamel formation in people of known breastfeeding history. A problem in earlier research on tooth development has been the lurking possibility that the deposition process varies among people in ways that make inferences about life history and diet transitions in prehistoric humans somewhat doubtful. A more extensive record of comparative work on breastfeeding and tooth development, with large human and primate samples, has the potential to test whether between-population and within-population variation in developmental processes is important here.

As the research develops, I keep reflecting on the plasticity of childhood development. Here we see breastfeeding as an influence upon the stable isotopes represented in teeth, but the teeth grow with or without that food source. One of the macaques showed a pulse of increased barium after being weaned entirely, which the authors suggest may have been caused by the release of barium and calcium from the skeleton and incorporation in the teeth. Our bodies use stored minerals within the skeleton as a reservoir for later biochemical needs, and acquisition of nutrients from the mother's bodily stores is an important part of that process. Human development relies upon buffers against environmental variability, and in certain physiological processes -- such as enamel formation -- we see a complex trace of those buffers interacting with extreme shifts in environmental resource availability.

This is a really complicated way of saying that our bodies have to cope with losing people, because our ancestors lost their parents much more often than we do today. The Scladina child was part of this heritage of survival.

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