The impact of imitative versus emulative learning mechanisms on artifactual variation: Implications for the evolution of material culture

Cultural evolutionary approaches highlight that different social learning processes may be involved in the maintenance of cultural traditions. Inevitably, for traditions to be maintained, they must be transmitted with reasonably fidelity. It has been proposed that 'imitation' (i.e., the direct copying of actions of others displayed in tasks such as toolmaking) generates relatively low rates of copying error. As such, imitation has often been ascribed an important role in the maintenance of traditions and in the 'ratcheting' of technological complexity over time. Conversely, 'emulation' (i.e., the copying of a result but not the behaviors that have led to that result) is allegedly associated with the production of relatively higher rates of copying error. However, to what extent these different social learning mechanisms generate distinct patterns of variation during the manufacture of material traditions remains largely unexplored empirically. Here, a controlled experiment was implemented using 60 participants who copied the shape of a 3D 'target handaxe form' from a standardized foam block. In an 'imitation condition', 30 participants were shown manufacturing techniques employed in the production of the target form and the target form itself. Conversely, in an 'emulation condition', 30 participants were shown only the (target) form. Copying error rates were statistically different, being significantly lower in the 'imitation' condition compared to the 'emulation' condition. Moreover, participants in the imitation condition matched the demonstrated behaviors with significantly higher copying fidelity than the alternative condition. These results illustrate that imitation may be imperative for the long-term perpetuation of visibly distinct archaeological traditions, especially in the case of lithic (reductive) traditions, where copying error rates can be expected to be relatively high. These findings, therefore, provide evidence that imitation may be required to explain the prolonged continuity of broad shape fidelity such as that seen in traditions of 'handaxe' manufacture during the Pleistocene.Leverhulme Trus

Copying error, evolution, and phylogenetic signal in artifactual traditions: An experimental approach using "model artifacts"

This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.Spatio-temporal patterns of artifactual variation are increasingly being studied via the explicit application of cultural evolutionary theory and methods. Such broad-scale (macroevolutionary) patterns are mediated, however, by a series of small-scale (microevolutionary) processes that occur at the level of individual artifacts, and individual artifact users and producers. Within experimental biology, "model organisms" have played a crucial role in understanding the role of fundamental microevolutionary processes, such as mutation and the inheritance of variation, in respect to macroevolutionary patterns. There has, however, been little equivalent laboratory work to better understand how microevolutionary processes influence macroevolutionary patterns in artifacts and their analysis. Here, we adopt a "model artifact" approach to experimentally study the issues of copy error (mutation) and resultant phylogenetic signal in artifact traditions. We used morphometric procedures to examine shape copying error rates in our "model artifacts." We first established experimentally that statistically different rates of copying error (mutation) could be induced when participants used two different types of shaping tool to produce copies of foam "artifacts." Using this as a baseline, we then tested whether these differing mutation rates led to differing phylogenetic signal and accuracy in two separate experimental transmission chains (lineages), involving participants copying the previous participant's artifact. The analysis demonstrated that phylogenetic reconstruction is more accurate in artifactual lineages where copying error is demonstrably lower. Such results demonstrate how fidelity of transmission impacts directly on the evolution of technological traditions and their empirical analysis. In particular, these results highlight that differing contexts of cultural transmission relating to fidelity might lead to differing patterns of resolution within reconstructed evolutionary sequences. Overall, these analyses demonstrate the importance of a "model artifact" approach in discussions of cultural evolution, equivalent in importance to the use of model organisms in evolutionary biology in order to better understand fundamental microevolutionary processes of direct relevance to macroevolutionary archaeological patterns.We are grateful to Noreen von Cramon-Taubadel, Robin Torrence, and our anonymous reviewers for helpful and constructive comments on this paper. This research was partly supported by the Leverhulme Trust (F/07 476/AR) and by the Research Foundation for the State University of New York

Differences in Manufacturing Traditions and Assemblage-Level Patterns: the Origins of Cultural Differences in Archaeological Data

AcceptedArticle in PressThis is the author accepted manuscript. The final version is available from Springer via the DOI in this record.© 2016 Springer Science+Business Media New York A relationship between behavioral variability and artifactual variability is a founding principle of archaeology. However, this relationship is surprisingly not well studied empirically from an explicitly “microevolutionary” perspective. Here, we experimentally simulated artifactual variation in two populations of “artifact” manufacturers, involving only a single behavioral difference in terms of their “tradition” of manufacturing tool. We then statistically analyzed shape variation in the resultant artifacts. In many respects, patterned differences might not have been expected to emerge given the simple nature of the task, the fact that only a single behavioral variable differed in our two populations, and all participants copied the same target artifact. However, multivariate analyses identified significant differences between the two “assemblages.” These results have several implications for our understanding and theoretical conceptualization of the relationship between behavior and artifactual variability, including the analytical potency of conceiving of artifacts as the product of behavioral “recipes” comprised of individual “ingredient” behavioral properties. Indeed, quite trivial behavioral differences, in generating microevolutionarily potent variability, can thus have long-term consequences for artifactual changes measured over time and space. Moreover, measurable “cultural” differences in artifacts can emerge not necessarily only because of a strict “mental template” but as the result of subtle differences in behavioral ingredients that are socially learned at the community level.We are grateful to Noreen von Cramon-Taubadel, Metin Eren, and the anonymous reviewers and editors at JAMT for helpful and constructive comments on this paper. This research was partly supported by the Leverhulme Trust (F/07 476/AR) and by the Research Foundation for the State University of New York

Considering the role of time budgets on copy-error rates in material culture traditions: an experimental assessment

This is the final version of the article. Available from the publisher via the DOI in this record.Ethnographic research highlights that there are constraints placed on the time available to produce cultural artefacts in differing circumstances. Given that copying error, or cultural 'mutation', can have important implications for the evolutionary processes involved in material culture change, it is essential to explore empirically how such 'time constraints' affect patterns of artefactual variation. Here, we report an experiment that systematically tests whether, and how, varying time constraints affect shape copying error rates. A total of 90 participants copied the shape of a 3D 'target handaxe form' using a standardized foam block and a plastic knife. Three distinct 'time conditions' were examined, whereupon participants had either 20, 15, or 10 minutes to complete the task. One aim of this study was to determine whether reducing production time produced a proportional increase in copy error rates across all conditions, or whether the concept of a task specific 'threshold' might be a more appropriate manner to model the effect of time budgets on copy-error rates. We found that mean levels of shape copying error increased when production time was reduced. However, there were no statistically significant differences between the 20 minute and 15 minute conditions. Significant differences were only obtained between conditions when production time was reduced to 10 minutes. Hence, our results more strongly support the hypothesis that the effects of time constraints on copying error are best modelled according to a 'threshold' effect, below which mutation rates increase more markedly. Our results also suggest that 'time budgets' available in the past will have generated varying patterns of shape variation, potentially affecting spatial and temporal trends seen in the archaeological record. Hence, 'time-budgeting' factors need to be given greater consideration in evolutionary models of material culture change.This work was funded by the Leverhulme Trust (Research Project Grant F/07 476/AR). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscrip

Factors affecting Acheulean handaxe variation: Experimental insights, microevolutionary processes, and macroevolutionary outcomes

PublishedJournal ArticleThis is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.The “Acheulean” is comprised of individual knapping events undertaken by individual hominins. In other words, it is a particular component of hominin behavior that we draw out and amalgamate into a wider “pattern.” The resultant phenomenon (i.e., “the Acheulean”) is an entity that stretches over the space of three continents and spans a time period in excess of one million years. If such an exercise has any merit, it is because it provides a means of comparative (behavioral) analysis over these swathes of time and space. Comparative research can document, measure, and statistically assess temporo-spatial patterns of artifactual variation, and so test hypotheses regarding the character of that variation. However, it does not provide an independent means of examining some of the key phenomena which it is necessary to further understand in order to increase our comprehension of this archaeological legacy. Here, we review and synthesize recent experimental work that we have undertaken, which has specifically investigated some of the factors potentially responsible for the generation and constraint of variation within the Acheulean techno-complex. We examine issues of raw material, copying errors, and their relationship to mechanisms of social learning. Understanding these microevolutionary factors via experiments, we contend, is essential in order to reach a secure understanding of the macroscale phenomenon typically referred to as the “Acheulean.” Moreover, we outline how a “quantitative genetic” framework to these issues provides an essential means of linking these inherent micro- and macro-evolutionary factors into a coherent whole, while also simultaneously reconciling the potential influence of different sources of variation that are part of a temporally and geographically dispersed entity such as the Acheulean.We thank Marie-Hélène Moncel and Daniele Schreve for their invitation to take part in this issue. We are also grateful to the four reviewers (Michael O'Brien and three anonymous), whose thoughtful and constructive comments on the manuscript were much appreciated. Much of the work reported in this paper was funded by the Leverhulme Trust

Development and feasibility testing of a smart phone based attentive eating intervention

BACKGROUND: Attentive eating means eating devoid of distraction and increasing awareness and memory for food being consumed. Encouraging individuals to eat more attentively could help reduce calorie intake, as a strong evidence base suggests that memory and awareness of food being consumed substantially influence energy intake. METHODS: The development and feasibility testing of a smartphone based attentive eating intervention is reported. Informed by models of behavioral change, a smartphone application was developed. Feasibility was tested in twelve overweight and obese volunteers, sampled from university staff. Participants used the application during a four week trial and semi-structured interviews were conducted to assess acceptability and to identify barriers to usage. We also recorded adherence by downloading application usage data from participants' phones at the end of the trial. RESULTS: Adherence data indicated that participants used the application regularly. Participants also felt the application was easy to use and lost weight during the trial. Thematic analysis indicated that participants felt that the application raised their awareness of what they were eating. Analysis also indicated barriers to using a smartphone application to change dietary behavior. CONCLUSIONS: An attentive eating based intervention using smartphone technology is feasible and testing of its effectiveness for dietary change and weight loss is warranted

Changing Patient and Public Beliefs About Antimicrobials and Antimicrobial Resistance (AMR) Using a Brief Digital Intervention.

BBackground: A key driver of antimicrobial resistance (AMR) is patient demand for unnecessary antibiotics, which is driven by patients’ beliefs about antibiotics and AMR. Few interventions have targeted beliefs to reduce inappropriate demand. Objective: To examine whether a brief, online algorithm-based intervention can change beliefs that may lead to inappropriate antibiotic demand (i.e. perceptions of antibiotic necessity and lack of concern about antibiotic harm). Design: Pre- and post-intervention study. Participants: Participants were 18 years or older, and residing in the United Kingdom, who self-selected to participate via Amazon mTurk, an online survey plaform, and via research networks. Intervention: Participants were presented with a hypothetical situation of cold and flu symptoms, then exposed to the intervention. The online intervention comprised: 1) a profiling tool identifying individual beliefs (antibiotic necessity, concerns, and knowledge) driving inappropriate antibiotic demand; 2) messages designed to change beliefs and knowledge (i.e. reduce antibiotic necessity, and increase antibiotic concerns and knowledge), and 3) an algorithm linking specific messages to specific beliefs and knowledge. Main measures: The profiling tool was repeated immediately after the intervention and compared with baseline scores to assess change in beliefs. A paired samples t-test was used to determine intervention effect. Key Results: A total of 100 respondents completed the study. A significant change in beliefs relating to inappropriate demand was observed after the intervention, with a reduction in beliefs about antibiotic necessity (t = 7.254; p < 0.0001), an increase in antibiotic concerns (t = −7.214; p < 0.0001), and increases in antibiotic and AMR knowledge (t = −4.651; p < 0.0001). Conclusion: This study is the first to demonstrate that patient beliefs about antibiotics and AMR associated with inappropriate demand can be changed by a brief, tailored online intervention. This has implications for the design of future interventions to reduce unnecessary antimicrobial use

Shared care obesity management in 3-10 year old children: 12 month outcomes of HopSCOTCH randomised trial

Objective: To determine whether general practice surveillance for childhood obesity, followed by obesity management across primary and tertiary care settings using a shared care model, improves body mass index and related outcomes in obese children aged 3-10 years. Design: Randomised controlled trial. Setting: 22 family practices (35 participating general practitioners) and a tertiary weight management service (three paediatricians, two dietitians) in Melbourne, Australia. Participants: Children aged 3-10 years with body mass index above the 95th centile recruited through their general practice between July 2009 and April 2010. Intervention: Children were randomly allocated to one tertiary appointment followed by up to 11 general practice consultations over one year, supported by shared care, web based software (intervention) or “usual care” (control). Researchers collecting outcome measurements, but not participants, were blinded to group assignment. Main outcome measures: Children’s body mass index z score (primary outcome), body fat percentage, waist circumference, physical activity, quality of diet, health related quality of life, self esteem, and body dissatisfaction and parents’ body mass index (all 15 months post-enrolment). Results: 118 (60 intervention, 56 control) children were recruited and 107 (91%) were retained and analysed (56 intervention, 51 control). All retained intervention children attended the tertiary appointment and their general practitioner for at least one (mean 3.5 (SD 2.5, range 1-11)) weight management consultation. At outcome, children in the two trial arms had similar body mass index (adjusted mean difference −0.1 (95% confidence interval −0.7 to 0.5; P=0.7)) and body mass index z score (−0.05 (−0.14 to 0.03); P=0.2). Similarly, no evidence was found of benefit or harm on any secondary outcome. Outcomes varied widely in the combined cohort (mean change in body mass index z score −0.20 (SD 0.25, range −0.97-0.47); 26% of children resolved from obese to overweight and 2% to normal weight. Conclusions: Although feasible, not harmful, and highly rated by both families and general practitioners, the shared care model of primary and tertiary care management did not lead to better body mass index or other outcomes for the intervention group compared with the control group. Improvements in body mass index in both groups highlight the value of untreated controls when determining efficacy.Melissa Wake, Kate Lycett, Susan A Clifford, Matthew A Sabin, Jane Gunn, Kay Gibbons, Cathy Hutton, Zoë McCallum, Sarah J Arnup, Gary Witter

Trial Protocol: Randomised controlled trial of the effects of very low calorie diet, modest dietary restriction, and sequential behavioural programme on hunger, urges to smoke, abstinence and weight gain in overweight smokers stopping smoking

Background\ud Weight gain accompanies smoking cessation, but dieting during quitting is controversial as hunger may increase urges to smoke. This is a feasibility trial for the investigation of a very low calorie diet (VLCD), individual modest energy restriction, and usual advice on hunger, ketosis, urges to smoke, abstinence and weight gain in overweight smokers trying to quit. \ud \ud Methods\ud This is a 3 armed, unblinded, randomized controlled trial in overweight (BMI > 25 kg/$m^2$), daily smokers (CO > 10 ppm); with at least 30 participants in each group. Each group receives identical behavioural support and NRT patches (25 mg(8 weeks),15 mg(2 weeks),10 mg(2 weeks)). The VLCD group receive a 429-559 kcal/day liquid formula beginning 1 week before quitting and continuing for 4 weeks afterwards. The modest energy restricted group (termed individual dietary and activity planning(IDAP)) engage in goal-setting and receive an energy prescription based on individual basal metabolic rate(BMR) aiming for daily reduction of 600 kcal. The control group receive usual dietary advice that accompanies smoking cessation i.e. avoiding feeling hungry but eating healthy snacks. After this, the VLCD participants receive IDAP to provide support for changing eating habits in the longer term; the IDAP group continues receiving this support. The control group receive IDAP 8 weeks after quitting. This allows us to compare IDAP following a successful quit attempt with dieting concurrently during quitting. It also aims to prevent attrition in the unblinded, control group by meeting their need for weight management. Follow-up occurs at 6 and 12 months. \ud \ud Outcome measures include participant acceptability, measured qualitatively by semi-structured interviewing and quantitatively by recruitment and attrition rates. Feasibility of running the trial within primary care is measured by interview and questionnaire of the treatment providers. Adherence to the VLCD is verified by the presence of urinary ketones measured weekly. Daily urges to smoke, hunger and withdrawal are measured using the Mood and Physical Symptoms Scale-Combined (MPSS-C) and a Hunger Craving Score (HCS). 24 hour, 7 day point prevalence and 4-week prolonged abstinence (Russell Standard) is confirmed by CO < 10 ppm. Weight, waist and hip circumference and percentage body fat are measured at each visit. \ud \ud Trial Registration\ud Current controlled trials ISRCTN83865809\ud \u