The formation of predictions is essential to our ability to build models of the world and use them for intelligent decision-making. Here we challenge the dominant assumption that humans form only forward predictions, which specify what future events are likely to follow a given present event. We demonstrate that in some environments, it is more efficient to use backward prediction, which specifies what present events are likely to precede a given future event. This is particularly the case in diverging environments, where possible future events outnumber possible present events. Correspondingly, in six preregistered experiments (n = 1,299) involving both simple decision-making and more challenging planning tasks, we find that humans engage in backward prediction in divergent environments and use forward prediction in convergent environments. We thus establish that humans adaptively deploy forward and backward prediction in the service of efficient decision-making.

预测的形成对于我们构建世界模型并将其用于智能决策的能力至关重要。在这里，我们挑战了人类仅形成前瞻性预测的主导假设，该预测指定了给定当前事件之后可能发生的未来事件。我们证明，在某些环境中，使用向后预测会更有效，它指定当前事件可能先于给定的未来事件。在不同的环境中尤其如此，未来可能发生的事件多于当前可能发生的事件。相应地，在涉及简单决策和更具挑战性的规划任务的六个预注册实验（ n = 1,299）中，我们发现人类在发散环境中进行后向预测，并在趋同环境中使用前向预测。因此，我们确定人类适应性地部署前向和后向预测以服务于高效决策。