The cognitive requirements of cumulative culture: experiments with typically developing and autistic people

Human culture accumulates and increases in complexity over generations, building on what came before. This phenomenon, termed cumulative cultural evolution, generates ever-more efficient tools and technologies and has helped humans to spread across the globe, but its causes remain mysterious. Many animals have simple forms of culture such as tools, foraging methods and social rituals that spread through groups by learning, but the cumulative nature of human culture seems to be unique in the animal kingdom. We will examine the cognitive processes that make human culture possible using experiments with autistic and typically developing (TD) people.

The most widely accepted explanation for cumulative cultural evolution is that it relies on a set of three cognitive processes that are rare or absent in other animals but allow humans to learn from each other with great accuracy and so build upon cultural knowledge. First, imitation: the ability to copy the others' precise actions. Second, teaching, whereby knowledgeable individuals actively help others learn. This is thought by psychologists to require Theory of Mind (ToM), the ability to reason about what others know and so correct their ignorance. Third, social attention: engaging others to work together to achieve joint goals. To date, firm evidence for this hypothesis is lacking and different studies have produced contradictory results. As deficits in imitation, ToM and social attention are among the key features of autism, experiments comparing autistic and TD people can help determine whether these processes are needed for cultural information to be passed on and accumulate.

We will use experiments to test whether imitation, teaching and social attention are required for cultural improvements in tools of differing levels of complexity. In one experiment, we will set up "transmission chains" of TD people where the first person makes a tool from everyday materials without any guidance, the second person can learn from the first, and so on. In a third of the chains participants will be able to watch and imitate the previous person. In another third, each participant will remain as a teacher to help the next person and in the remaining chains participants will simply see the final product made by the previous person. We predict that simple tools will become more efficient across all the chains, but for more complex tools imitation and teaching will be necessary to generate improvements. A second experiment will use groups of autistic and TD children working in pairs to make tools over eight rounds, with one member of the pair being replaced by a new child after each round. We expect the autistic children to show less social attention and teaching, so compared to the TD children their tools should show little improvement over the rounds.

Our other experiments will examine the common but untested assumption that human teaching requires ToM. Instead of reasoning about pupils' knowledge, people may also use visible indicators of pupils' abilities to deliver effective lessons. To test this, we will ask TD and autistic children to teach other children simple games and tool-using tasks. By varying the age of pupils and using "stooge" pupils that make deliberate mistakes we will find out whether autistic children, despite their ToM impairments, can deliver effective lessons targeted to the age and competence of their pupils. Finally, we will examine a specialised form of human teaching, motherese: the simplified and exaggerated baby-talk used by parents across cultures that appears to help babies learn to speak. We propose that motherese may not require ToM but is in fact an automatic human response to baby-like features. This may explain why people speak in a similar way to babies and cute pets. If we are correct, then autistic children, despite their ToM deficits, will show similar patterns to TD children in experiments where they are asked to talk to a dog, a baby or an adult

In addition to its academic impact, this work will generate substantial benefits for the wider community.

SCIENTIFIC ENGAGEMENT AND EDUCATION

This project addresses the cognitive processes underlying the extraordinary cultural richness that has enabled human beings to become the dominant species on Earth. It is therefore perfectly placed to attract public interest and develop scientific engagement with the wider community. This is particularly important as our research encompasses topics that are widely misunderstood. For instance, the media commonly portrays a misleading view of human behaviour as being caused either by nature or nurture; biology or culture. We will help foster a more nuanced understanding which acknowledges that the capacity for culture has biological roots and cultural traits themselves change by processes analogous to biological evolution. Similarly, the public are often faced with simplistic caricatures of Autistic Spectrum Disorders. We aim to promote a greater understanding and consideration of autism as a cognitive style rather than just a disability and to highlight the potential for autistic people to make important contributions to society. Finally, the collaborative nature of our research will serve as a useful example of the nature of scientific progress. A critical but underappreciated aspect of science is its unpredictability - when the PI began working on wild meerkats ten years ago, he never imagined it might lead to testable hypotheses about mechanisms of teaching in people with autism. As knowledge progresses beyond traditionally delimited fields, interdisciplinary collaboration is also increasingly important, as illustrated by the diverse research backgrounds of the PI and Co-Is, bridging evolutionary biology and animal behaviour, experimental psychology and cognitive neuroscience. We all have extensive experience of public engagement, including international press coverage and television documentaries based on our research (BBC2, Channel 4, NHK Japan) and we will make use of this to develop a comprehensive engagement strategy encompassing social media, websites, public talks and press (see Pathways to Impact). By recruiting volunteers to take part in our experiments and providing information about the aims and background of the study, we will also help to educate and engage non-scientists in research.

AUTISM COMMUNITY AND SPECIAL EDUCATION

We aim to benefit the autistic community both by promoting public understanding and by developing practical benefits from our research. We will engage children, parents and teachers as active participants in our research and solicit their views and comments. We will also consult experts in special education and hold a workshop for carers, teachers and academics with the ultimate aim of developing proposals for evidence-based pedagogical tools in special education.

SOCIAL IMPACT

Progressive improvements in tools and technologies are essential engines of economic prosperity. By revealing the cognitive processes that make cumulative cultural evolution possible, our work therefore has important practical implications for maximising technological progress. Our work may also help unlock untapped societal contributions. Businesses are slowly beginning to recognise that autistic people often exhibit striking talents, and this is reflected in recent drives by software companies to recruit autistic people as programmers (http://www.bbc.co.uk/news/business-22621829). Our work will help to build on these important developments by examining means by which autistic people may teach and so pass on their skills to others.

TRAINING

This project will provide comprehensive training in diverse research techniques and transferable skills for a postdoctoral research assistant, a research assistant and several internship students.