Dunbar & Schultz take on the ambitious and contested explanation for why primates have unusually large brains. They posit that this was driven by group size and complexity. As they reason to this conclusion, they highlight how previous literature on the subject of evolutionary brain growth has unfortunately only focused on restraints to brain growth rather than selective pressures acting on this. Their analysis examines both qualitative and quantitative social bonds, taking them from highlighting pair-bonding as a driver of brain growth in vertebrates (qualitative) to the evidently unique association of group size and complexity with brain size found in primates (quantitative). They reason that in vertebrates, pair-bonding acted as a selective pressure on brain growth. However, in primates, this level of bonding became present between non-potential mates. Thus, as the type of bonds found among mates of a pair-bonded species emerged in primates among non-mating members, group size and complexity became the selective pressure on primate brain size instead of pair-bonding, as observed in other vertebrates.
 
A strength I found with this article was its aim to move away from constraint explanations for brain growth, rightly highlighting the fact that just because an organism can evolve a larger brain does not mean this will be the case. A good example of this problem is in the “Expensive Tissue Hypothesis” by Aiello & Wheeler (1995). They reason that a reduction in the human gut allowed for an increase in brain size, and they create ratios of expected versus observed energy demands per major organ in different primate species. This led them to find that while other major organs in humans were observed similarly to their expected energy demands, the human gut required much less energy than expected while the brain required much more than expected. They concluded that there was a pretty clean “swap” of energy demands from the gut to the brain. However, while this is interesting, the authors were criticized for the very same thing Dunbar & Schultz mention; they explained lifting constraints, but there was no reason for why this energy would be going towards a larger brain. To be fair, the authors responded by saying they were only suggesting that this created a “prime allower” for brain growth, and that they were not suggesting a “prime mover” for brain growth. I think this highlights why constraint research can be valuable as a complement to research on primate (and specifically human in this case) brain growth (side note; there is still controversy over the cause for human gut size reduction, while Aiello & Wheeler posit meat eating, Wrangham posits cooking).
 
Another point certainly worthy of mention in this article is its call for niche construction research, though this is only very briefly mentioned. They claim that, “In effect, we are dealing explicitly with multi-level selection and the long-overlooked topic of niche construction” (1346). Mackinnon & Fuentes (2012) carry this torch much further. They define niche construction as “modification of the functional relationship between organisms and their environment by actively changing one of the factors in that environment” (73). They explain the mind-numbingly complex continuous interactions between primates and their social and ecological environments, in which they can strategically alter their environment, which then at the same time acts upon their evolutionary fitness. Applying this to what Dunbar & Schultz are claiming, primates form groups not in the interest of immediate personal fitness, but in the interest of long-term payoffs in fitness (reduced predation is one example provided) that lead to overall net fitness gains for the individuals over the course of their lifetime, which is made possible by group fitness (the authors mention a “trickle-down” effect going from group fitness to individual fitness).
 
After making vast species comparisons of pair-bonding and brain size, Dunbar & Schultz find that primates are unique, in that there is not a significant difference between pair-bonding species and non-pair-bonding species in relation to brain size. This leads them to the conclusion that primates must utilize the type of bonds seen in pair-bonds of mates of other vertebrate species with non-mates. However, one problem with this (I am hesitant to call this a weakness, as the authors bring it up themselves) is the difficulty in understanding and studying “bonded-ness”. In understanding bonded-ness in humans, the authors warn against what they have observed, in which researchers attempt to put forth a single hormone or single gene to explain bonded-ness. Rather, they note the likely complexity and many contributions influencing the unique bonds among and between primates.
 
In the interest of studying bonded-ness from a neuroanthropological perspective, it may prove insightful to utilize the combination of ethnographic work (attempting to capture the meanings crafted by individuals regarding their bonds) along with research tools provided by neuroscience such as fMRI’s. If this produces any noteworthy findings, then studies of the brains of other primates could add another element through comparisons with humans. For example, Dunbar & Schultz note the limits of ethology, as what is going on inside the animal is left much to question. However, if studies of human understanding and meaning making regarding their bonds (both with mates and non-mates), combined with neuroscience methodology (such as brain scanning), these findings could potentially be applied to other primate species in order to (very roughly) approximate understanding and meaning making in other primates, thus capturing what has been elusive to ethologists in understanding what is going on inside the animal.

 
Sources:
 
Aiello, L. C., & Wheeler, P. (1995). The expensive-tissue hypothesis: the brain and the digestive system in human and primate evolution. Current Anthropology, 199-221.
 
Dunbar, R. I., & Shultz, S. (2007). Evolution in the social brain. Science, 317(5843), 1344-1347.
 
MacKinnon, K. C., & Fuentes, A. (2012). Primate social cognition, human evolution, and niche construction: a core context for neuroanthropology. The encultured brain, ed. Daniel H. Lende and Greg Downey, 67-102.
 
Wrangham, R. (2009). Catching fire: How cooking made us human. Basic Books.

MacKinnon and Fuentes (2012) draw on the literature of primatology to place human sociality in a broader phylogenetic context. This context allows us to understand humans as part of a pattern in evolutionary history, which associates increased sociality with increasingly large brains. Placing ourselves within larger evolutionary patterns also allows us to see how our social behavior might be different from that of non-human primates. What is clear in this chapter is that behavioral flexibility has allowed many different primates to exploit myriad environments in many different ways. MacKinnon and Fuentes (2012) use the example of variation in food processing within the same species in the same type of environments to illustrate this point. This variation must be understood not only in terms of ecology, but also in terms of the social traditions of particular groups within species.
 
The authors illustrate the use of theories and methods like niche construction and social network analysis for a better understanding of how social and ecological selective forces are integrated in the production of the social primate brain, and how this brain enhances selective fitness. The particularly long period of post-natal brain growth in genera like Homo, Pan, and Cebus allows for the deep integration of social learning into the developing brain. This period of development is crucial for learning how to navigate (social) selective landscapes successfully, which call simultaneously for competition and cooperation with variable actors. The authors ultimately agree with scholars like Dunbar, arguing that social intelligence (enabled by expanded brain volume and longer periods of postnatal brain development) was a major determinant of darwinian success in human evolution.
 
I found the niche construction section of this reading useful. Rather than conceiving of social competitors, foraging problems, predator avoidance, etc. as independent selective pressures calling for specific adaptive strategies on the part of the individual, it is useful to think about how social behavior and ecology are integrated. Niche construction theory helps to provide a plausible account of how human brain evolution could have occurred; however, I am left wondering if the social brain hypothesis isn’t another “just-so” story. It is certainly conceivable that larger brains enabled more cooperation, increasingly complex communication, more efficient exploitation of the environment, a greater range of exploitable habitats, etc., but how could we disprove this hypothesis?
 
I might be more convinced by the social brain hypothesis if there were neurological models of how the social brain could have developed through evolutionary time. What specific changes occurred in brain structure and circuitry in human evolutionary history that allowed for the development of such a uniquely social brain? It is necessary to talk about changes in brain volume, but this only part of the story. I think this is the sort of perspective a neuroanthropologist might contribute to primate studies of cognition and the social brain hypothesis.
 
I am admittedly ignorant when it comes to methodology in primate studies, but I assume primate studies work with small samples, often in an artificial laboratory environment, with evidence from the field sometimes taking the form of anecdotes. I was therefore impressed with some of the literature cited having to do with social network analysis. In particular, I was impressed by the very large amount of data being integrated into the study of primate social networks related to kinship, particular behaviors such as grooming, and how these different networks interact to produce population level patterns in social behavior. This reading left me with an improved impression of primatology studies.
 
This chapter clearly demonstrates the utility of theory and method in primatology for a better understanding of humans. It helps us answer big questions: why are humans so social? Where does our capacity for culture come from? Thus, taking the brain as a given in neuroanthropological research would be a mistake. More productive research will no doubt conceive of the brain as a product of specific evolutionary processes, which impact on how our brain develops and functions in everyday settings. This is a tangible contribution of primatology to neuroanthropology, and this area of research deserves further investigation.
 
References
 
MacKinnon, Katherine C., and Agustín Fuentes
   2012    Primate Social Cognition, Human Evolution, and Niche Construction: A Core Context
               for Neuroanthropology. In The Encultured Brain: An Introduction to
               Neuroanthropology. Daniel H. Lende and Greg Downey, eds. Pp. 67-102. Cambridge:
               The MIT Press.

In his article, “What Is Normal? A Historical Survey and Neuroanthropological Perspective”, Mason culturally situates the concept of “normal”. Drawing from cross-cultural research, he highlights how behaviors that may be viewed as disruptive in one culture may be neutral or even positively integrated into another, such as depression versus being a good Buddhist. Mason also looks at the concept of normality historically, highlighting how the meaning has changed over time. His historical survey touches on witch hunts, the development of statistics, and drug use. In all cases, Mason highlights how the idea of normal was wrapped up in power relations at the expense of those who were not considered normal. Next, he critically examines the term degenerate, and provides an alternative definition to the value-loaded common understanding of the word. Instead of this definition, Mason highlights its use in biological systems theory as meaning when different structures can perform the same function. In conclusion, Mason calls for a value-free operational conceptualization of degeneracy (as it is defined in biological systems theory), a focus on human diversity in neuroscience research, and extensive self-reflection on the most basic assumptions of our scientific culture.
 
I found numerous strengths in this article, including the attention paid to the negative consequences resulting from determinations of normalcy, the current role of consumerism (as people strive to be normal or ideal), and the alternative conceptualization of degenerate. While Mason shows the extreme consequences of the (ab)normal label, such as prison sentences for certain drug uses, the implementation and justification of racial caste systems, and death as a result of a witch hunt, he also highlights more subtle consequences such as the influence a professional diagnosis of being abnormal can have on job attainment and status, being viewed by the state as a capable parent, or the potentially altered state of other mental conditions. These potential consequences certainly justify the critical self-reflection Mason calls for.
 
Mason also highlights the role of consumerism, in which individuals are exposed to images of what is ideal, and what is ideal becomes equated with what is normal. Thus, individuals are sold products with the promise of getting closer to, but never actually achieving, the ideal. Mason briefly mentions the involvement of pharmaceutical companies in consumerism, a topic further explored by Hunt et al. (2013). They found that diagnosis criteria are lowering for diabetes, hypertension, and high cholesterol, particularly for minority groups considered to be at higher risk. The result is that the parameters of normal shrink, while the parameters of abnormal grow, resulting in increased diagnoses and increased prescribing (to the point where side effects to prescriptions are treated with more prescriptions).
 
Another major strength is the alternative conceptualization of degenerate Mason provides. This conceptualization comes from biological systems theory, in which multiple structures can perform the same function. According to this conceptualization, there is not a “one-to-one” structure function relationship. Mason highlights how this can help us understand variation rather than try to erase or ignore it. For example, he notes that mental states and disorders are essentialized and viewed as stable or static. However, brain scanning research has shown that individuals determined to be normal can have brain scans that indicate pathology, while individuals determined as having pathology can have brain scans that look like a brain determined to be normal. Thus, different structures of the brain may be performing similar functions, rather than the conventional thought that one structure performs one function.
 
One important weakness to this article is that it could have been more constructive on how to go about putting into practice the conclusions provided. While this is understandable given the space allotted and the intentions of the article, much is left to the reader to figure this out. Regarding the call for critical self-reflection, directing the reader to Roepstorff & Frith (2012) would have been helpful, as they focus on methodology in that respect. However, the most sizeable hurdle is how to put into practice a value-free operational conceptualization of degeneracy. Viewing mental states as dynamic and embracing rather than masking and ignoring diversity, as Mason mentions, seems like a plausible first step. However, this could problematize diagnoses, as cutoffs (or clear parameters for what is considered “normal”) are likely needed in order to determine when intervention is needed. This article does not offer a “magic bullet” on how to study and treat mental states, though this may (and I would bet it is) intentional.
 
References:
 
Hunt, L., Kreiner, M., & Rodriguez-Mejia, F. (2013). Changing Diagnostic and Treatment Criteria for Chronic Illness: A Critical Consideration of Their Impact on Low-Income Hispanic Patients. Human organization, 72(3), 242-253.
 
Mason, P. H. (2015). What Is Normal? A Historical Survey and Neuroanthropological Perspective. In Handbook of Neuroethics (Eds.) J. Clausen & N. Levy (pp. 343-363). Springer Netherlands.
 
For further reading on degeneracy in biological systems theory:
 
Edelman, G. M., & Gally, J. A. (2001). Degeneracy and complexity in biological systems. Proceedings of the National Academy of Sciences, 98(24), 13763-13768.
 
Friston, K. J., & Price, C. J. (2003). Degeneracy and redundancy in cognitive anatomy. Trends In Cognitive Sciences, 7(4), 151-152.
 
Noppeney, U., Friston, K. J., & Price, C. J. (2004). Degenerate neuronal systems sustaining cognitive functions. Journal of Anatomy, 205(6), 433-442.

​To answer our thematic question that asks, “What is Neuroanthropology?” I pose that the most complete answer thus far is found in the second chapter of our text. Downey and Lende, as advocates of this new branch of anthropology, say that “neuroanthropology posits that subjectivity and the brain meet in the things that people do and say and the ways we interact with one another and the environment” (2012, p. 41). For me, this quotation wraps up the entirety of this chapter as well as provides an intriguing springboard from which we can leap as we develop an interest and sound methodology within this field and beyond it.

Similarly to what we discussed in our very first class, neuroanthropology at its core is all about weaving together strings from other fields into studying human beings, their environments, brains, and everything in between. Downey and Lende make a great case in setting neuroanthropology apart from other fields such as psychology and neuroscience in order to answer shortcomings that are inherent within each of these fields. In sharing a timeline for the development of neuroanthropology, they criticize the mass modularity theory that had taken root in these fields because it assumes that brain function and structure are universal across individuals and groups.

My personal favorite is the false assumption that brains are inflexible which plagued the social sciences around the 1980s. This was an area of great interest to me because within the field of education, often teachers, parents, and students continue to assume that they have a fixed level of intelligence and that their minds cannot adapt to their new environment or surroundings. (See this lovely Wikipedia page for more information.) These theories of intelligence have behavioral ramifications for their behavior with regards to learning which, to me, exemplifies the necessity for a field that integrates brain science with the rigorous research methods of anthropology. I completely agree with the authors as they argue that speaking to the endless, and highly nuanced, variations in human thoughts, behaviors, and neurological makeup is a critical next step in not only the social sciences, but also the brain sciences as well. With regards to all of this, I am excited to see that, along with integrating information and theory from a variety of fields, neuroanthropology’s grounding in anthropology means that defining terms like culture and applying quality field-based research methods are at the heart of this field.

Again, in agreement with Downey and Lende, I agree that culture is a term that is often used as a side note to the variables that we study, even in educational psychology, and that redefining the boundaries of this concept matters to how we study the brain. Their definition of culture includes the shared representations of a group of people and extends it to include the variations within the nervous system as well as the material world. As a second year student on the track for specializing in educational neuroscience, this is by far the most complete and coherent definition of culture because it incorporates the material world of human biology into the meanings and representations that encompass human existence. This definition speaks to the embodiment of thought in a way that my colleagues and I have pondered, but have not been able to put into a concise phrase.

Overall, this chapter and it’s look from the past to the future of neuroanthropology gives me hope that people haven’t studied everything yet.  It allows me to dream about the things that we have yet to uncover. And it gives me the tools and language to carry these discoveries into new territory.

​Downey, G. & Lende, D. H. (2012). Neuroanthropology and the encultured brain. In D. H. Lende & G. Downey (Eds.), The encultured brain: An introduction to neuroanthropology (pp. 23-65). Cambridge, MA: Massachusetts Institute of Technology Press.

   ​         Upon the arrival of every new conceptual/scientific framework, criticism by the discipline’s veterans inevitably follows. In this article, Roepstorff and Frith take on the burgeoning field of neuroanthropology, arguing that a new discipline called “neuroanthropology” is unnecessary, that what the proposed field of “neuroanthropology” really is, is just “anthropology.” They further argue that the proposed mechanism of neuroanthropology, “experimental” in analogy to laboratory work, is too unwieldy, rejects Anthropology’s strength as a phenomenological science, and attempts research designs at which cultural anthropology is decidedly weak. Instead, they say, “experimental” anthropology is best practiced as (a) “an anthropological study of experiments” or (b) “an aesthetics of research practice” (105). Finally, they acknowledge and attempt to fit into their own framework previous work done in neuroanthropology on cognitive processes, neurological effects of ritual, and cultural notions of identity and selfhood. Roepstorff and Frith make some good points in their assessment of the previous work done, but their assertion that neuroanthropology be better left as anthropology is ultimately unconvincing.
         Roepstorff and Frith rightly point out that the strengths of (cultural) anthropology do not include experimental laboratory work. It is a broad context- and meaning-based science that does not easily lend itself to the stringent, narrow, and necessarily highly controlled conditions of laboratory experiments. Even lab work done by biological anthropologists, although controlled as well as possible, is not done without difficulty (in terms of biomarker collection) and concerns about validity (in terms of the representativeness of the sample). Further, Roepstorff and Frith bring up the danger of over-interpreting brain scans and inadvertently racializing found cultural differences by reifying them as biological entities. However, this can be (relatively) easily to overcome by recognizing and addressing these weaknesses, and by further utilizing interdisciplinarity in conducting research.
         That said, what valid concerns they have are either addressed by Downey and Lende (2012), or do not invalidate “neuroanthropology” as a framework. Their main argument is that what neuroanthropology is purportedly set to accomplish is not so much a new epistemological framework as it is an extension of “experimental anthropology,” defined as (a) method (i.e., lab work), (b) object of study (i.e., an “anthropology of experiments”), and (c) research aesthetic (i.e., trying out novel ways of doing anthropology). Personally, I found this to be nonsensical, and my immediate reaction to the idea of “experimental anthropology” was “so what?” It seemed like a double standard, because the way I understand neuroanthropology from my readings so far in The Encultured Brain is an anthropology of the nervous system/neurological phenomena in the same way that medical anthropology is the broad study of how humans engage with health or that psychological anthropology can range from studies of ethnopsychology to cross-cultural manifestations of psychological phenomena. This is decidedly greater in scope than an “anthropology of experiments,” but not necessarily un-doable. Further, what is “experimental anthropology” but another loosely defined theoretical framework that is ultimately “just” Anthropology? The same argument made against “neuroanthropology” can be made against “experimental anthropology.”
            While Roepstorff and Frith argue that a narrowed field of neuroanthropology is unwarranted, they don’t fully engage the “so what?” that their argument begs. They say that it is best left as “anthropology,” or considered an extension of “experimental anthropology,” but the evidence for their argument was unconvincing. What good points they did make are recognized and addressed by those who support the field. Ultimately, their argument seemed more like a petty disagreement about semantics than a valid criticism about conceptual framework, and belied a lack of understanding of what neuroanthropology does and can represent. Or, maybe, it was a subconscious extension of the lumper-splitter dilemma entrenched in physical anthropology by paleoanthropologists. Either way, their points are made and well-taken, but not enough to stymie the growth of this new and exciting field.

Roepstorff, A., & Frith, C. (2012). Neuroanthropology or simply anthropology? Going experimental as method, as object of study, and as research aesthetic. Anthropological Theory, 12(1), 101-111.