Does diversity deliver? How variation in individual knowledge and behavioural traits impact on the performance of animal groups

你是否曾经和一群朋友（或者更糟的是同事）站在一个陌生的城市里，试图选择去哪家餐馆吃饭？我想是的，但你还记得你是如何做出选择的吗，一直努力团结在一起，不失去彼此？有很多方法可以让你做出决定。你可能会听从小组成员的决定，特意沿着高街走，或者你们都同意去那个对这个城市很了解的人说的“镇上最好的”餐馆。这种情况在动物世界中也很常见。把“餐馆”换成“觅食地”，我们就得到了几乎所有群居动物每天都要面对的觅食决定的描述。但这些都不是微不足道的决定；一些连续的错误选择——当一个群体被带到贫瘠的觅食区，或危险的栖息地——可能是致命的。当动物面临意想不到的危险或不断变化的环境时，做出这样的决定就更加困难了，在我们这个快速变化的世界里，所有动物都越来越多地遇到这种情况。动物群体应对不确定性并在这样的环境中表现良好的一种方法是利用彼此的特定专业知识或信息，或者让个体足够大胆地尝试新的选择。例如，我们知道汇总个体群体成员所拥有的信息可以增加群体的集体认知，这一概念在媒体上引起了很大的关注，被称为“群体的智慧”。更大和/或更多样化的群体也可能包含具有不同技能和经验的个人，这增加了一个群体解决给定任务的机会。但到目前为止，明确调查这种多样性对团队表现影响的研究，迄今为止仅限于以经济利益为目的的人类团队，而且得出的结果好坏参半。在拟议的奖学金中，我将结合实验和理论数据来检验“多样性带来”在群体环境中的假设，并提出这样的问题：是什么造就了一个获胜的团队？为了回答这个问题，我将向群居性很强的淡水鱼九刺鱼提出一系列类似于“哪家餐馆？”的例子。结合对单个鱼类运动的高度复杂的视频跟踪，以及使用厨房鸡蛋计时器和实验室培养皿制作的觅食设备，我将探索个体知识和个性变化的作用。我要解决的问题包括：如果一个群体中最见多识广的人同时也是这个群体中最大胆的人，那么这个群体是否会因为遵循这个大胆的人的选择而做出更准确的决定？如果一个群体是由多数信息贫乏的大胆个体和少数信息灵通的害羞个体组成的，那么这个群体是否能够利用后者所拥有的信息？一个群体的信息或个性组成要有多大的不同，他们才能在觅食的地方达成一致，然后分裂？所提出的独特实验设置也将使我能够在这些不同的环境中测量对个体鱼的实际益处（就食物的摄入量而言）。所有这些实验都将以5条鱼为一组进行，考虑到单独评估个体个性和训练不同水平的“专业知识”所需的时间。然而，我将使用一系列基于我在这些实验中发现的计算机模拟来预测50或100个人的鱼群的结果，然后我将在实验室进行测试。总的来说，这个项目将是第一次尝试操纵群体内信息和个性的分布，并将为社会动物在应对不确定性时多样性的功能提供新的见解。

Have you ever been stood with a group of friends (or worse, colleagues) in an unfamiliar city trying to choose which restaurant to dine at? I expect so, but do you remember how you made your choice, all the while trying to stick together and not lose one another? There are a number of ways you could have arrived at your decision. You may have followed the decision of the group member who set-off purposefully down the High Street, or you all may have agreed to go to the restaurant declared 'the best in town' by the person with local knowledge of the city. Such situations are just as common in the animal world. Swap 'restaurant' to 'foraging patch' and we have a description for the type of foraging decisions faced by almost all social animals, every day of their lives. But these are not trivial decisions; a number of consecutive bad choices-where a group are led to poor foraging areas, or risky habitats-can be fatal. Such decisions are made even more difficult where animals face unexpected dangers or an environment which is constantly changing, something all animals are increasingly encountering in our rapidly changing world. One way animal groups may cope with uncertainty-and perform well in such environments-is by drawing upon one another's particular expertise or information, or having individuals bold enough to try out new options. For instance, we know that summing information possessed by individual group-members can increase the collective cognition of groups, a concept which has attracted much attention in the media and been termed 'the wisdom of crowds'. Larger and/or more diverse groups may also contain individuals with different skills and experiences, which increase the chances of a group solving a given task. But to date, studies that explicitly investigate the effect of such diversity on group performance have so far been restricted to human teams acting for financial gain, and have produced mixed results. In the proposed fellowship, I will use a combination of experimental and theoretical data to test the hypothesis that 'diversity delivers' in a group setting, and ask: What makes a winning team? To answer this question, I will present highly gregarious freshwater fish, the nine-spined stickleback, with a series of problems not unlike the 'which restaurant?' example I used in my opening sentences. Combining highly sophisticated video tracking of individual fishes movements, with foraging devices made using kitchen egg-timers and laboratory petri dishes, I will explore the role of variability in individual knowledge and personality. Questions I will tackle will include: If the most informed individual in a group is also the boldest in the group, does the group make more accurate decisions as a consequence of following this bold individual's choices? If a group is composed of a majority of poorly informed bold individuals and a minority of well-informed shy individuals, is the group able to utilise the information possessed by the latter? How different does a groups information or personality composition have to be before they cannot agree on a place to forage, and split up? The unique experimental set-up proposed will also allow me to measure the actual benefit to individual fish (in terms of amount of food eaten) in these different contexts. All of these experiments will take place with groups of just five fish, given the time needed to individually assess individual personality and train fish to different levels of 'expertise'. However, I will then use a series of computer simulations based on what I find in these experiments to make predictions about the outcome where shoals of fifty or a hundred individuals are concerned, which I will then test in the laboratory. Overall, this project will be the first attempt to manipulate the distribution of both information and personality within groups, and will provide a new insight into the function of diversity for social animals when coping with uncertainty.