Publications of Helena Miton

A Forward Bias in Human Profile‐Oriented Portraits

The spatial composition of human portraits obeys historically changing cultural norms. We show that it is also affected by cognitive factors that cause greater spontaneous attention to what is in front rather in the back of an agent. Scenes with more space in front of a directed object are both more often produced and judged as more aesthetically pleasant. This leads to the prediction that, in profile‐oriented human portraits, compositions with more space in front of depicted agents (a “forward bias”) should be over‐represented. By analyzing a large dataset (total N of 1,831 paintings by 582 unique identified European painters from the 15th to the 20th century), we found evidence of this forward bias: Painters tended to put more free space in front of, rather than behind, the sitters. Additionally, we found evidence that this forward bias became stronger when cultural norms of spatial composition favoring centering became less stringent.

Motor constraints influence cultural evolution of rhythm

While widely acknowledged in the cultural evolution literature, ecological factors—aspects of the physical environment that affect the way in which cultural productions evolve—have not been investigated experimentally. Here, we present an experimental investigation of this type of factor by using a transmission chain (iterated learning) experiment. We predicted that differences in the distance between identical tools (drums) and in the order in which they are to be used would cause the evolution of different rhythms. The evidence confirms our predictions and thus provides a proof of concept that ecological factors—here a motor constraint—can influence cultural productions and that their effects can be experimentally isolated and measured. One noteworthy finding is that ecological factors can on their own lead to more complex rhythms.

Utilizing simple cues to informational dependency

Studies have shown that participants can adequately take into account several cues regarding the weight they should grant majority opinions, such as the absolute and relative size of the majority. However, participants do not seem to consistently take into account cues about whether the members of the majority have formed their opinions independently of each other. Using an evolutionary framework, we suggest that these conflicting results can be explained by distinguishing evolutionarily valid cues (i.e. they were present and reliable during human evolution) from other cues. We use this framework to derive and test five hypotheses (H1 to H5). Our first three experiments reveal that participants discount majority opinion when the members of the majority owe their opinions to the same hearsay (H1), owe their opinions to having perceived the same event (H2), or owe their opinions to a common motivation (H3). Experiment 4 suggests that, by contrast, participants do not discount majority opinion when the members of the majority owe their opinions to sharing similar cognitive traits (H4). Finally, Experiment 5 suggests that participants adequately discount majority opinion when one of the members of the majority is untrustworthy (H5). This set of experiments shows that participants can be quite skilled at dealing with informational dependency, and that an evolutionary framework helps make sense of their strengths and weaknesses in this domain.

When iconicity stands in the way of abbreviation: No Zipfian effect for figurative signals

Zipf’s law of abbreviation, relating more frequent signals to shorter signal lengths, applies to sounds in a variety of communication systems, both human and non-human. It also applies to writing systems: more frequent words tend to be encoded by less complex graphemes, even when grapheme complexity is decoupled from word length. This study documents an exception to this law of abbreviation. Observing European heraldic motifs, whose frequency of use was documented for the whole continent and over two large corpora (total N = 25115), one medieval, one early modern, we found that they do not obey a robust law of abbreviation. In our early modern corpus, motif complexity and motif frequency are positively, not negatively, correlated, a result driven by iconic motifs. In both our corpora, iconic motifs tend to be more frequent when more complex. They grew in popularity after the invention of printing. Our results suggest that lacking iconicity may be a precondition for a graphic code to exhibit Zipf’s Law of Abbreviation.

Detecting wholesale copying in cultural evolution

A cultural practice can spread because it is transmitted with high fidelity, but also because biased transformation leads to its reinvention. The respective effect of these two mechanisms, however, may only be quantified if we can measure and detect high-fidelity transmission. This paper proposes wholesale copying, the reproduction of a set of elements as a set, as an operational definition. Using two corpus of heraldic designs (total n = 13,453), we apply information-theoretic tools to detect cases of wholesale copying and gauge their incidence. Heraldic designs are composed according to rigorous combinatorial rules. Wholesale copying causes the frequency of a design to increase out of proportion with the frequency of the motif and tinctures that make it up. Comparing the frequency of designs with that of their component motifs and tinctures, we show that the amount of information carried by a design tracks its inheritance along family lines. A model predicting the frequency of heraldic designs based solely on the frequency of their component parts systematically outperforms one that assumes a mix of wholesale copying and random mutation (with realistic mutation rates). These findings are consistent with low but non-null incidences of wholesale copying in the diffusion of heraldic designs.

Cumulative culture in the laboratory: methodological and theoretical challenges

In the last decade, cultural transmission experiments (transmission chains, replacement, closed groups and seeded groups) have become important experimental tools in investigating cultural evolution. However, these methods face important challenges, especially regarding the operationalization of theoretical claims. In this review, we focus on the study of cumulative cultural evolution, the process by which traditions are gradually modified and, for technological traditions in particular, improved upon over time. We identify several mismatches between theoretical definitions of cumulative culture and their implementation in cultural transmission experiments. We argue that observed performance increase can be the result of participants learning faster in a group context rather than effectively leading to a cumulative effect. We also show that in laboratory experiments, participants are asked to complete quite simple tasks, which can undermine the evidential value of the diagnostic criterion traditionally used for cumulative culture (i.e. that cumulative culture is a process that produces solutions that no single individual could have invented on their own). We show that the use of unidimensional metrics of cumulativeness drastically curtail the variation that may be observed, which raises specific issues in the interpretation of the experimental evidence. We suggest several solutions to these mismatches (learning times, task complexity and variation) and develop the use of design spaces in experimentally investigating old and new questions about cumulative culture.

Developmental and cultural factors in economic beliefs

Boyer & Petersen (B&P) assume that the intuitive systems underlying folk-economic beliefs (FEBs), and, in particular, emporiophobia, evolved in the environment of evolutionary adaptedness (EEA), before markets. This makes the historical development of markets puzzling. We suggest that what evolved in the EEA are templates that help children develop intuitive systems partly adjusted to their cultural environment. This helps resolve the puzzle.

Willingness to transmit and the spread of pseudoscientific beliefs

Pseudoscientific beliefs are widespread and can be damaging. If several studies have examined the factors leading people to accept pseudoscientific beliefs, no attention has been paid to the factors contributing to people's willingness to transmit these beliefs. To test whether the willingness to transmit pseudoscientific beliefs contributes to their spread, independent of their believability, we asked participants to rate statements corresponding either to pseudoscientific beliefs (Myths), or to their (correct) negations (Non‐Myths). Statements were rated on believability, on how willing participants would be to transmit them, and on how knowledgeable they would make someone who produces them. Results revealed that participants who believed in Myths were more willing to transmit them than the participants who believed in Non‐Myths were willing to transmit Non‐Myths. A potential factor driving the increased willingness to transmit both Myths and Non‐Myths might be participants' belief that holding the beliefs makes one seem more knowledgeable.