一项研究发现，切胸蚁个体与整个群体在一个感知任务中的相对成绩取决于任务的困难程度。科研人员长久以来就认识到了社会动物在进行以实现目标为中心的任务时所展示的群体智力的优势。为了确定在某些情况下个体的见解是否会超过群体智力，Takao Sasaki及其同事训练了以寻找巢穴技能闻名的切胸蚁，让它们在两个质量条件不同的巢址中选择更好的一个，巢的质量条件是由内部亮度水平代表的。这组作者报告说，不同的巢址选择之间的定性差别是小的，蚂蚁群体更可能比蚂蚁个体选择两个巢址中的更好的一个。相比之下，当这些选择的定性差异大的时候，个体在选择更好的地址上的表现超过了群体，这提示群体的智慧在困难的感知和区别任务上比简单的任务更有优势。这组作者使用一个数学模型发现了群体成员之间的正反馈可以帮助群体整合信息并且在需要感知微小差异的任务中超过个体的表现。然而，这样的一种反馈机制可能导致群体在执行相对简单的感知任务的时候做出次优的选择。这组作者说，这些发现可能帮助确定选择性使用个体判断和集体决策的情况。（生物谷 Bioon.com）
原文标题：群体智慧接受检验
生物谷推荐的英文摘要
PNAS doi: 10.1073/pnas.1304917110
Ant colonies outperform individuals when a sensory discrimination task is difficult but not when it is easy
Takao Sasakia,1, Boris Granovskiyb, Richard P. Mannb, David J. T. Sumpterb, and Stephen C. Pratta
“Collective intelligence” and “wisdom of crowds” refer to situations in which groups achieve more accurate perception and better decisions than solitary agents. Whether groups outperform individuals should depend on the kind of task and its difficulty, but the nature of this relationship remains unknown. Here we show that colonies of Temnothorax ants outperform individuals for a difficult perception task but that individuals do better than groups when the task is easy. Subjects were required to choose the better of two nest sites as the quality difference was varied. For small differences, colonies were more likely than isolated ants to choose the better site, but this relationship was reversed for large differences. We explain these results using a mathematical model, which shows that positive feedback between group members effectively integrates information and sharpens the discrimination of fine differences. When the task is easier the same positive feedback can lock the colony into a suboptimal choice. These results suggest the conditions under which crowds do or do not become wise.
