Flexibility and generativity are fundamental aspects of functional behavior that begin in infancy and improve with experience. How do infants learn to tailor their real-time solutions to variations in local conditions? On a nativist view, the developmental process begins with innate prescribed solutions, and experience elaborates on those solutions to suit variations in the body and the environment. On an emergentist view, infants begin by generating a variety of strategies indiscriminately, and experience teaches them to select solutions tailored to the current relations between their body and the environment. To disentangle these accounts, we observed coordination patterns in 11-month-old pre-walking infants with a range of cruising (moving sideways in an upright posture while holding onto a support) and crawling experience as they cruised over variable distances between two handrails they held for support. We identified infants’ coordination patterns using a novel combination of computer-vision, machine-learning, and time-series analyses. As predicted by the emergentist view, the least experienced infants generated multiple coordination patterns inconsistently regardless of body size and handrail distance, whereas the most experienced infants tailored their coordination patterns to body-environment relations and switched solutions only when necessary. Moreover, the beneficial effects of experience were specific to cruising and not crawling, although both skills involve anti-phase coordination among the four limbs. Thus, findings support an emergentist view and suggest that everyday experience with the target skill may promote “learning to learn,” where infants learn to assemble the appropriate solution for new problems on the fly.

灵活性和生成性是功能性行为的基本方面，从婴儿期开始并随着经验而提高。婴儿如何学会根据当地条件的变化来定制他们的实时解决方案？从先天论的观点来看，发展过程始于先天规定的解决方案，经验会详细说明这些解决方案以适应身体和环境的变化。从涌现论的观点来看，婴儿开始时会不加选择地产生各种策略，经验教会他们选择适合他们身体与环境之间当前关系的解决方案。为了解开这些账户，我们观察了 11 个月大的步行前婴儿的协调模式，当他们在两个扶手之间游弋时，他们具有一系列巡航（以直立姿势侧向移动，同时抓住支撑物）和爬行体验。我们使用计算机视觉、机器学习和时间序列分析的新组合确定了婴儿的协调模式。正如紧急情况论所预测的那样，无论身体大小和扶手距离如何，经验最少的婴儿都会不一致地产生多种协调模式，而经验最丰富的婴儿会根据身体-环境关系调整他们的协调模式，并仅在必要时切换解决方案。此外，经验的有益效果是特定于巡航而不是爬行，尽管这两种技能都涉及四肢之间的反相位协调。因此，研究结果支持了一种紧急情况的观点，并表明目标技能的日常经验可能会促进“学习学习”，即婴儿学会在飞行中为新问题组装适当的解决方案。