The greater male variability phenomenon predicts that males exhibit larger ranges of variation in cognitive performance compared with females; however, support for this pattern has come exclusively from studies of humans and lacks mechanistic explanation. Furthermore, the vast majority of the literature assessing sex differences in cognition is based on studies of humans and a few other mammals. In order to elucidate the underpinnings of cognitive variation and the potential for fitness consequences, we must investigate sex differences in cognition in non-mammalian systems as well. Here, we assess the performance of male and female food-caching birds on a spatial learning and memory task and a reversal spatial task to address whether there are sex differences in mean cognitive performance or in the range of variation in performance. For both tasks, male and female mean performance was similar across four years of testing; however, males did exhibit a wider range of variation in performance on the reversal spatial task compared with females. The implications for mate choice and sexual selection of cognitive abilities are discussed and future directions are suggested to aid in the understanding of sex-related cognitive variation.

中文翻译：

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测试更大的雄性变异现象：与雌性相比，雄性山雀在逆向学习表现方面表现出更大的变化

更大的男性变异现象预示着与女性相比，男性在认知能力方面表现出更大的变化范围；然而，对这种模式的支持完全来自对人类的研究，缺乏机械解释。此外，绝大多数评估认知性别差异的文献都是基于对人类和其他一些哺乳动物的研究。为了阐明认知变异的基础和健康后果的可能性，我们还必须调查非哺乳动物系统中认知的性别差异。在这里，我们评估了雄性和雌性食物缓存鸟类在空间学习和记忆任务和逆转空间任务中的表现，以解决在平均认知表现或表现变化范围内是否存在性别差异。对于这两个任务，在四年的测试中，男性和女性的平均表现相似；然而，与女性相比，男性在逆向空间任务上的表现确实表现出更大范围的变化。讨论了认知能力对配偶选择和性选择的影响，并提出了未来的方向，以帮助理解与性别相关的认知变异。