アブストラクト
美的価値に対する、文化的に埋め込まれた知覚的反応にまつわる研究によると、学習された知覚的能力は、社会規範への遵守を確保する。それゆえに、物理的環境に応じて変化する認知プロセス（例えば知覚）と、社会規範によって形成される認知プロセス（例えば経済的意思決定）との間に線引きするという誘惑には、抵抗する必要がある。社会規範に従うことが物理的環境の知覚可能な特徴を変化させるならば、知覚学習は結果として、社会規範への遵守をもたらす。
Abstract
A study of culturally-embedded perceptual responses to aesthetic value indicates that learned perceptual capacities can secure compliance with social norms. We should therefore resist the temptation to draw a line between cognitive processes, such as perception, that can adapt to diferences in physical environments, and cognitive processes, such as economic decision-making, that are shaped by social norms. Compliance with social norms is a result of perceptual learning when that same compliance modifes perceptible features of the physical environment.
In “The Weirdest People in the World?”, Henrich et al. (2010) principally target assumptions behind methods that generalize from the cognitive performance of some human populations to all populations. As it turns out, populations vary in performance across a huge range of tasks. The paper should give anyone pause who is reasoning from samples. At the same time, the paper raises substantive questions about cognition and culture. To what extent is cognition infuenced by culture? Conversely, to what extent is it unifed across populations? That raises a further question: how should we individuate the populations across which cognition varies? What are the units of cultural explanation? Answering these two questions means addressing a more fundamental question: what explains variation in cognition across populations? Some of the variation is due to environmental diferences; some stems from diferences in social norms. This paper argues that some variation in perceptual performance is determined by social norms. In particular, learned perceptual capacities secure compliance with social norms that govern aesthetic cultures.
(1) どの程度、文化は認知に影響するか
(2) （それによって文化を区別するような）文化の本質[nature]は何か
(3) 文化はどのように認知に影響するか
Questions about (1) the extent of cultural infuence on cognition and (2) the nature of culture depend for their answers on asking (3) how culture infuences cognition. Answers to the three clusters of questions interact.
Start with (1). Henrich, Heine, and Norenzayan contrast evidence of varying performance with evidence of uniform performance covering a wide swath of cognitive phenomena. Strikingly, it would have been impossible to predict in advance what varies by population and what does not. Populations vary when it comes to some perceptual illusions, spatial cognition, folk biological reasoning, self-conception, reasoning style, moral reasoning, and economic decision-making. They are invariant when it comes to other perceptual illusions, reading facial expressions, false belief tasks, psychological essentialism, and dealing with free riders.
Even when performance varies by population, it does not follow that the underlying cognitive processes vary. One and the same cognitive process might produce diferent outputs in diferent settings. What appear to be two processes might be one process, when the process is individuated more broadly. What determines whether a process is to be individuated broadly or narrowly? The answer can only be that processes individuate as required by the best explanation of the relevant facts. As a result, when the data indicate variation in performance by population, we must consider what features of those populations might explain the variance. Starting at (1), we are led to (3).
The path from (1) to (3) traverses (2), questions about what cultures are, the units of cultural explanation. Henrich, Heine, and Norenzayan organize their presentation around telescoping contrasts: industrialized versus small-scale societies, Euro versus non-Euro industrialized societies,1 subjects in the United States versus those in other industrialized societies, and subjects in the US sorted by level of education. This organization is meant to be “rhetorical” and “should not be taken as capturing any unidimensional continuum, or suggesting any single theoretical explanation for the variation” (Henrich et al. 2010: 62). It is an open question how to carve up populations that vary cognitively. That is, it is an open question what features specifc to populations might explain the variances in cognition. Again, we are led to (3).
The Müller-Lyer illusion belongs to a class of illusions whose strength varies by population (Henrich et al. 2010: 64 reporting Segall et al. 1966). The strength of the illusion is measured by the length of the lines when the lines are manipulated to the point where a subject sees them as the same length. In other words, the illusion is stronger in those for whom there is a larger diference in line length when the lengths appear the same. So measured, the illusion is strongest among US subjects, and it almost vanishes among San foragers in the Kalahari. The result is surprising, especially for those who take vision to be a low-level, modular process that is impermeable to culture (e.g. Fodor 1983). In keeping with their methodological slant, Henrich, Heine, and Norenzayan ask, “if visual perception can vary, what kind of psychological processes can we be sure will not vary?” (2010: 64–65). Slanting instead to the substantive issues, we ask, how could responses to the illusion vary (also see Machery 2010)?
Henrich, Heine, and Norenzayan do endorse a hypothesis defended by Segall et al. (1966). Vision adapts to recurring features of the local physical environment. The environments of carpenter cultures, which abound with corners, favor “optical calibrations and visual habits” that generate the Müller-Lyer illusion. San, who forage the Kalahari, do not inhabit an environment where carpentered corners calibrate and habituate vision in the same way. Notice that the explanation of the variation is that visual learning trains visual capacities fit for local physical environments. The unit of cultural explanation is populations inhabiting physical environments that are shaped by culture.
By contrast, take economic decision-making (Henrich et al. 2010: 65–66). In the Ultimatum Game, subjects are given a sum of money and instructed that they must ofer a portion to another player, but both forfeit the money if the ofer is rejected. WEIRD subjects tend to ofer 40 to 50 % of the sum, and amounts below 30 % are often rejected. Subjects from the smallest-scale societies, where social interaction is principally face-to-face, make and accept much lower ofers. Setting aside the challenges to methods in behavioral economics, we can ask what would explain the variation. Henrich, Heine, and Norenzayan ofer a hypothesis. Diferent populations comply with diferent norms of economic decision-making, so that “what behavioral economists have been measuring… is a specifc set of social norms, culturally evolved for dealing with money and strangers, that have emerged since the origins of agriculture and the rise of complex societies” (Henrich et al. 2010: 66). Notice now that the explanation of the variation refers to social norms that govern interaction among agents. The unit of cultural explanation is therefore populations of people interacting with one another in compliance with social norms
In sum, variations in performance with respect to the Müller-Lyer illusion and the Ultimatum Game seem to be explained by appeal to diferent mechanisms, implicating diferent units of cultural explanation. Variation in performance with respect to the Müller-Lyer illusion is explained by visual learning, which trains visual capacities suited to local physical environments, and the unit of cultural explanation is populations inhabiting physical environments. Variation in performance with respect to the Ultimatum Game is explained by compliance with diferent social norms, and the unit of cultural explanation is populations interacting with one another socially.