Evolution of Sex Differences in Spatial Ability

在人类和实验动物中，在涉及空间思维的任务中，男性通常比女性表现得更好。该领域以前的工作试图通过关注性激素、大脑组织和差异体验的相对直接影响，来解释男性和女性在一生中空间能力的性别差异是如何发生的。到目前为止，这种差异的进化和发展部分几乎没有受到关注。高林博士提出了一个巧妙的假设，即进化过程有利于空间能力的性别差异。高林博士提出，对于活动范围更大的动物来说，进化对空间能力的培养作用更强：要想成功定位，拥有较大活动范围的动物比活动范围较小的动物需要更多的空间技能。为了测试这一富有想象力的想法，他选择了几种关系密切的野生啮齿动物，这些物种在活动范围和繁殖策略上存在主要差异。一些物种是一夫多妻制的，另一些是一夫一妻制的。他发现，一夫多妻制的物种比亲缘关系密切但一夫一妻制的物种有更大的栖息地。高林博士预测，在一夫一妻制物种中，如果雄性和雌性的活动范围大小相似，就不会发现空间能力的差异。相反，在一夫多妻制物种中，雄性的活动范围比雌性大得多，他预测这些雄性在他的实验室任务中会比雌性表现得更好。高林博士正在结合实地和实验室工作来解决这个重要问题。每只雄性和雌性田鼠的活动范围是通过无线电遥测测量的，方法是为每只动物安装微型无线电发射器，并跟踪它们的活动数周。在野外工作之后，他重新捕获了这些动物，并在实验室里测量了它们的迷宫学习能力。目前的拨款支持使他能够继续这些研究，最初由美国国家科学基金会拨款BNS85-08436资助。这些正在进行的研究的结果将为生态学和学习理论提供基本重要的信息，并最终可能增强我们对影响人类学习能力的因素的了解。

In both humans and laboratory animals, males typically perform better than females on tasks that involve spatial thinking. Previous work in this field has tried to explain how sex differences in spatial ability occur during the lifetimes of males and females by focusing on the relatively immediate effects of sex hormones, brain organization and differential experience. Until now, the evolutionary and developmental components of this difference have received little attention. Dr. Gaulin has developed the ingenious hypothesis that sex differences in spatial ability have been favored by the evolutionary process. Dr. Gaulin proposes that evolution fosters spatial ability more strongly for more mobile animals: To orient successfully, an animal with a large home range needs more spatial skill than does an animal with a smaller range. To test this imaginative idea, he has chosen several closely related species of wild rodents which differ primarily in range size, and in reproductive strategies. Some species are polygamous, others monogamous. He has found that polygamous species have larger home ranges than members of closely related, but monogamous, species. Dr. Gaulin predicts that in monogamous species, where males and females have similar range sizes, no differences in spatial abilities will be found. Conversely, in the polygamous species, where males have much larger range sizes than do females, he predicts that these males will perform better in his laboratory tasks than do the females. Dr. Gaulin is combining both field and laboratory work to address this important question. Home ranges of individual male and female voles are measured using radio-telemetry, by fitting individual animals with miniaturized radio transmitters and following their movements for several weeks. Following the field work, he recaptures these same animals and measures their maze- learning ability in the laboratory. The current grant support is allowing him to continue these studies, originally funded by NSF grant BNS 85-08436. The results of these ongoing studies will contribute information of fundamental importance to ecology and to learning theory, and may eventually enhance our knowledge of factors that influence learning ability in humans.