Olivier Morin

We hypothesize that fictional stories are highly successful in human cultures partly because they activate evolved cognitive mechanisms, for instance for finding mates (e.g., in romance fiction), exploring the world (e.g., in adventure and speculative fiction), or avoiding predators (e.g., in horror fiction). In this paper, we put forward a comprehensive framework to study fiction through this evolutionary lens. The primary goal of this framework is to carve fictional stories at their cognitive joints using an evolutionary framework. Reviewing a wide range of adaptive variations in human psychology–in personality and developmental psychology, behavioral ecology, and evolutionary biology, among other disciplines –, this framework also addresses the question of interindividual differences in preferences for different features in fictional stories. It generates a wide range of predictions about the patterns of combinations of such features, according to the patterns of variations in the mechanisms triggered by fictional stories. As a result of a highly collaborative effort, we present a comprehensive review of evolved cognitive mechanisms that fictional stories activate. To generate this review, we (1) listed more than 70adaptivechallengeshumans faced in the course of their evolution, (2) identified the adaptive psychological mechanisms that evolved in response to such challenges, (3) specified four sources of adaptive variability for the sensitivity of each mechanism(i.e., personality traits, sex, age, and ecological conditions), and (4) linked these mechanisms to the story features that trigger them. This comprehensive framework lays the ground for a theory-driven research program for the study of fictional stories, their content, distribution, structure, and cultural evolution.

Naturalistic approaches to culture face an adjustment problem: many entities commonly found in the social sciences (traditions, institutions, social norms, etc.) do not seem to have any plausible counterpart in the natural sciences that are closest to humans (biology and psychology). The natural world seems too tiny to accommodate the furniture of the social world. There are two ways around this problem. The first consists in trying to add new elements to our biological and psychological toolkit that may explain cultures, institutions, and norms. For example, one might hypothesize that special faculties of imitation and processes of group-selection allowed cultural norms to emerge and constrain individuals, or that humans have a special capacity to create institutions by means of collective intentionality. Cultural epidemiologists, in contrast, try to give descriptions of cultural phenomena that do not include such unwieldy objects as cultural forces, collective intentions, mind-coercive norms, and such. A culture, in the epidemiological view, is a distribution of representations within a population. Being a statistical abstraction, this distribution lacks an essence and causal powers. Cultural representations are transmitted in the same way as representations that never become cultural; they just spread further and survive longer. They do so, not because they travel the superhighway of imitation—there need not be such a highway—but because their content makes them more attractive to individual human minds. People from different cultures may view the world differently in many cases, but that is not because their culture puts some sort of constraint on their ideas; in these cases, their ideas and their culture are the very same thing. The epidemiological approach is a way to deflate our common views about culture, so that it no longer seems to outstretch the natural world. The two strategies are not incompatible. When trying to fit two pieces together, it makes sense to shrink one of the pieces while enlarging the other.

Trying to preserve cultural forms as faithfully as possible is a key motivation for cultural transmission. This paper reviews two possible accounts of it. One, evolutionary conservatism, is premised on the superiority of accumulated cultural knowledge compared to individual judgement – a theme that runs strongly through both the cultural evolution literature and conservative political philosophy. I argue for a clear distinction between evolutionary conservatism, and status quo conservatism as motivated by loss- and risk-aversion. I proceed to tackle some outstanding issues regarding status quo conservatism: its association with attachment to social hierarchies; the kind of cultural practices that tend to elicit it; and the question why an attitude motivated by considerations of costs and benefits might be manifested as a rigid or absolute principle. Seeing some cultural practices as equilibria in a coordination game helps answer these questions.

This pre-registered replication study explores the impact of perceived cuteness on the evolution of cultural artifacts, testing whether neotenic traits – eye size, forehead height, and head roundness – have increased in teddy bears over time. In previous research, Hinde & Barden (1980) found an increase in teddy bear neoteny while Gould (1985) found that Mickey Mouse’s features became more neotenic with time. However, both studies lacked statistical power (15 teddy bears and 3 Mickey Mouse drawings). We collected data from eight major teddy bear manufacturers over nine decades (N = 250; 1900–1980). We found that the forehead height of teddy bears significantly increased over time. Conversely, our prediction that heads became rounder and eyes became bigger were not supported. We outline four key methodological limitations that future research should address to deepen our understanding of the cultural evolution of cuteness and of cultural artifacts more broadly – i.e., sampling bias, metadata inaccuracy, categorization ambiguity, and function ambiguity.

Efficiency principles are increasingly called upon to study features of human language and communication. Zipf's law of abbreviation is widely seen as a classic instance of a linguistic pattern brought about by language users’ search for efficient communication. The “law”—a recurrent correlation between the frequency of words and their brevity—is a near-universal principle of communication, having been found in all of the hundreds of human languages where it has been tested, and a few nonhuman communication systems as well. The standard explanation for the law of abbreviation derives from pressures for efficiency: speakers minimize their cumulative effort by using shorter words for frequent occurrences. This explanation, we argue here, fails to explain why long words exist at all. It also fails to explain why the law of abbreviation, despite being robust, is systematically weakened by many short and rare words. We propose an alternative account of the law of abbreviation, based on a simple cultural evolutionary model. Our model does not require any pressure for efficiency. Instead, it derives the law of abbreviation from a general pressure for brevity applying to all words regardless of their frequency. This model makes two accurate predictions that the standard model misses: the correlation between frequency and brevity is consistently weak, and it is characterized by heteroskedasticity, with many short and rare words. We argue on this basis that efficiency considerations are neither necessary nor sufficient to explain the law.

Discovering the meaning of novel communicative cues is challenging and amounts to navigating an unbounded hypothesis space. Several theories posit that this problem can be simplified by relying on positive expectations about the cognitive utility of communicated information. These theories imply that learners should assume that novel communicative cues tend to have low processing costs and high cognitive benefits. We tested this hypothesis in three studies in which toddlers (N = 90) searched for a reward hidden in one of several containers. In all studies, an adult communicated the reward's location with an unfamiliar and ambiguous cue. We manipulated the processing costs (operationalized as inferential chain length) and cognitive benefits (operationalized as informativeness) of the possible interpretations of the cues. Toddlers processing of novel communicative cues were guided by expectations of low processing costs (Study 1) and high cognitive benefits (Studies 2 and 3). More specifically, toddlers treated novel cues as if they were easy to process, informative, and accurate, even when provided with repeated evidence to the contrary. These results indicate that, from toddlerhood onward, expectations of cognitive utility shape the processing of novel communicative cues. These data also reveal that toddlers, who are in the process of learning the language and communicative conventions of people around them, exert a pressure favoring cognitive efficiency in communicative systems.

This response takes advantage of the diverse and wide-ranging series of commentaries to clarify some aspects of the target article, and flesh out other aspects. My central point is a plea to take graphic codes seriously as codes, rather than as a kind of visual art or as a byproduct of spoken language; only in this way can the puzzle of ideography be identified and solved. In this perspective, I argue that graphic codes do not derive their expressive power from iconicity alone (unlike visual arts), and I clarify the peculiar relationship that ties writing to spoken language. I then discuss three possible solutions to the puzzle of ideography. I argue that a learning account still cannot explain why ideographies fail to evolve, even if we emancipate the learning account from the version that Liberman put forward; I develop my preferred solution, the “standardization account,” and contrast it with a third solution suggested by some commentaries, which says that ideographies do not evolve because they would make communication too costly. I consider, by way of conclusion, the consequences of these views for the future evolution of ideography.

An ideography is a general-purpose code made of pictures that do not encode language, which can be used autonomously – not just as a mnemonic prop – to encode information on a broad range of topics. Why are viable ideographies so hard to find? I contend that self-sufficient graphic codes need to be narrowly specialized. Writing systems are only an apparent exception: At their core, they are notations of a spoken language. Even if they also encode nonlinguistic information, they are useless to someone who lacks linguistic competence in the encoded language or a related one. The versatility of writing is thus vicarious: Writing borrows it from spoken language. Why is it so difficult to build a fully generalist graphic code? The most widespread answer points to a learnability problem. We possess specialized cognitive resources for learning spoken language, but lack them for graphic codes. I argue in favor of a different account: What is difficult about graphic codes is not so much learning or teaching them as getting every user to learn and teach the same code. This standardization problem does not affect spoken or signed languages as much. Those are based on cheap and transient signals, allowing for easy online repairing of miscommunication, and require face-to-face interactions where the advantages of common ground are maximized. Graphic codes lack these advantages, which makes them smaller in size and more specialized.

The amount of information conveyed by linguistic conventions depends on their precision, yet the codes that humans and other animals use to communicate are quite ambiguous: they may map several vague meanings to the same symbol. How does semantic precision evolve, and what are the constraints that limit it? We address this question using a multiplayer gaming app, where individuals communicate with one another in a scaled-up referential game. Here, the goal is for a sender to use black and white symbols to communicate colors. We expected that the players’ mappings between symbols and colors would grow more specific over time, through a selection process whereby precise mappings are preferentially copied. We found that players become increasingly more precise in their use of symbols over the course of their interactions. This trend did not, however, result from selective copying of precise mappings. We explore the implications of this result for the study of lexical ambiguity, Zipf's Law of Meaning, and disagreements over semantic conventions.