Within-Cultural Variation and the Scope of Cultural Neuroscience

Chiao and colleagues (this issue) describe a multidisciplinary field that has recently debuted and it is clear that in only a relatively short time has made substantial progress and a number of exciting discoveries. In this commentary, I first offer some general remarks on the emergence of the field and highlight some aspects that seem particularly promising. I then describe three issues that the authors did not seem to address in their article, including (a) the possible complications of variation and heterogeneity within a single culture, (b) the need to carve out the scope of cultural neuroscience and have a working definition of “culture,” and (c) the promise of using neuroscience to constrain cultural psychological theory. I then end with some conclusions. Given such advancement in our science that we are even seeing the emergence of this field, it seems striking that we are still at a time when, to many outside the field, the mere phrase “cultural neuroscience” may seem like an oxymoron: “What do culture and the brain have anything to do with one another?” We have known for a long time that sociocultural environments affect behavior and perceptual, cognitive, and affective processes (e.g., Heine, 2008; Nisbett, Peng, Choi, & Norenzayan, 2001), but the notion that they may affect brain function and structure may sometimes seem astounding. Consider, for example, a press statement released by the Association for Psychological Science (2010): “Where you grow up can have a big impact on the food you eat, the clothes you wear, and even how your brain works.” Examples of such statements abound in the media. They make clear that many people continue to make a critical distinction between culture shaping the mind and culture shaping the brain. Indeed, as Kitayama and Tompson (2010) noted, even we as researchers may accept clear cultural differences in a behavioral phenomenon but nevertheless find it intriguing just “to see how deep culture might go ‘under the skin”’ and how deeply it might infiltrate underlying neural mechanisms (p. 97). And of course, it is intriguing and exciting. It highlights the immense power of culture. It connects incredibly disparate levels of analysis, from high-level sociocultural processes to low-level changes in neural structure and function. As most would agree, however, such cultural infiltration into neural mechanisms should hardly surprise us. It is a reaction that reflects a legacy of Cartesian dualism deeply embedded in our folk psychology: that the mind and brain are rigidly separable. Whereas a psychological process may be readily shaped by culture, cultural influences on a neural process are for some reason deeper and realer; they are material rather than “immaterial.” However, any experiential shaping of perception, cognition, or behavior must by definition reflect an experiential shaping of the brain—as how else could such psychological differences arise? Although it may seem surprising that culture can influence neural activation patterns that are detected with even relatively insensitive brain-imaging methods (which can only assess coarse neural details), it should not be surprising per se that there exists a neural difference underlying a psychological difference. That should be an axiomatic assumption, not an empirical question. Cultural neuroscience prioritizes that assumption. It is a rigorous and scientifically mature approach going against the very grain of the mind–body dualism that still seems prevalent among the general public and entrenched within our folk psychology. Chiao et al. provide an exciting and promising view of a burgeoning field that already appears to have gained tremendous momentum. One thing that struck me about the field’s progress, as outlined by the authors, is a rapid growth of studies examining culture–gene interactions, with researchers examining cultural and genetic factors and how their unique interplay drives cognitive, neural, and behavioral processes. Ambady and Bharucha, in their review on cultural neuroscience in 2009, made a distinction between “cultural mapping” and “source analysis” approaches. Whereas cultural mapping involves mapping cultural patterns (e.g., in behavior or cognition) to neural patterns (e.g., fMRI activations), source analysis involves the perhaps trickier task of finding out the actual causes of those differences (or commonalities). The cultural mapping approach, they noted, had by far dominated the extant literature at that time. Chiao et al.’s review, however, suggests that the two approaches have now reached a more equal share. Examining how culture, genes, and their interactions together determine neural processes represents a powerful source analysis approach, and it is impressive that in only a few years since the 2009 review we are seeing a wealth of studies employing newer, more comprehensive approaches. With that said, however, one constraint on development in the source analysis approach to cultural neuroscience will