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

人类文化在前人的基础上，经过几代人的积累和复杂性的增加。这种现象被称为累积文化进化，产生了越来越有效的工具和技术，并帮助人类遍布地球仪，但其原因仍然是神秘的。许多动物都有简单的文化形式，如工具，觅食方法和社会仪式，通过学习在群体中传播，但人类文化的累积性似乎是动物王国中独一无二的。我们将通过对自闭症患者和正常发育（TD）人群的实验来研究使人类文化成为可能的认知过程。对累积文化进化最广泛接受的解释是，它依赖于一组三个认知过程，这些过程在其他动物中很少见或不存在，但允许人类非常准确地相互学习，从而建立文化知识。第一，模仿：模仿他人精确动作的能力。第二，教学，即知识渊博的个人积极帮助他人学习。心理学家认为这需要心理理论（ToM），即对他人所知进行推理并纠正其无知的能力。第三，社会关注：让其他人一起努力实现共同目标。迄今为止，这一假设缺乏确凿的证据，不同的研究产生了相互矛盾的结果。由于模仿、心理理论和社会注意力的缺陷是自闭症的主要特征之一，因此，通过比较自闭症患者和TD患者的实验，可以帮助确定这些过程是否是文化信息传递和积累所必需的。我们将通过实验来测试在不同复杂程度的工具中，模仿、教学和社会注意力是否是文化改进所必需的。在一个实验中，我们将建立TD人的“传输链”，第一个人在没有任何指导的情况下用日常材料制作工具，第二个人可以向第一个人学习，依此类推。在三分之一的链中，参与者将能够观看和模仿前一个人。在另外三分之一的链中，每个参与者将继续作为老师帮助下一个人，而在其余的链中，参与者将只看到前一个人制作的最终产品。我们预测，简单的工具将在所有链中变得更有效，但对于更复杂的工具，模仿和教学将是必要的。第二个实验将使用自闭症和TD儿童的小组，两人一组，在八轮中制作工具，每轮后一名成员被一个新的孩子取代。我们预计自闭症儿童的社会关注和教学较少，因此与TD儿童相比，他们的工具在几轮中应该没有什么改进。我们的其他实验将检验人类教学需要ToM这一常见但未经验证的假设。人们也可以使用学生能力的可见指标来提供有效的课程，而不是对学生的知识进行推理。为了验证这一点，我们将要求TD和自闭症儿童教其他儿童简单的游戏和使用工具的任务。通过改变学生的年龄和使用故意犯错误的“傀儡”学生，我们将发现自闭症儿童，尽管他们的心理理论障碍，是否可以提供针对学生年龄和能力的有效课程。最后，我们将研究人类教学的一种特殊形式，母亲语：不同文化的父母使用的简化和夸张的婴儿谈话，似乎可以帮助婴儿学习说话。我们建议，motherese可能不需要理论，但实际上是一个自动的人类反应婴儿般的功能。这可以解释为什么人们对婴儿和可爱的宠物说话的方式相似。如果我们是正确的，那么自闭症儿童，尽管他们的心理理论缺陷，将显示类似的模式，以TD儿童在实验中，他们被要求与狗，婴儿或成人交谈

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