男女有别在大脑?科学家对此说法不一
2015/12/03
男性大脑和女性大脑是否存在差异?这是科研界一直存在争议的热门话题。一些研究人员坚持认为男性、女性大脑存在差异,也有一些科学家认为大脑并不存在绝对的差异,而人们行为、性格等差异则是受到后天影响。那么,真相到底是什么?至今并无定论。


男性大脑和女性大脑是否存在差异?这是科研界一直存在争议的热门话题。一些研究人员坚持认为男性、女性大脑存在差异,也有一些科学家认为大脑并不存在绝对的差异,而人们行为、性格等差异则是受到后天影响。那么,真相到底是什么?至今并无定论。

从解剖学角度而言,男性和女性身体结构的差异能够一目了然,但是涉及到大脑结构,却不能简单地以性别差异对其进行绝对分类。近一个世纪以来,科学家都在努力确定男女大脑是否会像我们的生殖器官一样,因男女性别而存在差别。

男女大脑存在差异?男性脑容量大,女性大脑皮质厚……

通常,男性更为理智,女性则更偏于感性,且这种思维差异会反映在行为差别上。这又是为什么呢?早在2013年就有科研团队认为男女大脑存在根本性性别差异:男性的两个脑半球内部连接比女性多,男性大脑在数学和推理上存在更大脑容量,而女性大脑在同理心和合作上表现出优势。

如果我们的大脑确实存在性别差异,那么男性大脑和女性大脑之间就应该存在明显的区别。科学家为此进行了大量研究工作。2014年有实验室整合了超过100份关于大脑结构差异的研究结果,对其进行荟萃分析(meta-analysis)后发现:(1)男性大脑比女性大脑平均大8%-13%;(2)大脑中控制语言、记忆、情感和行为的区域也会因性别存在大小差异。

大脑不存在性别差异?多数大脑混合有男性和女性大脑特征

上述研究认为大脑存在男性和女性两种分化。但是近期,以色列特拉维夫大学的研究团队提出不一样的论断:大多人的大脑处于中间状态,同时拥有男性和女性的特性。也就是说,很多情况下以性别分类人的大脑没有意义,因为大多数人具有男性和女性大脑特征的混合,人类大脑不能被划分成截然不同的两种类型。

研究人员选取112个男性和169个女性为研究对象,通过磁共振成像(MRI)技术对大脑体积、大脑区域连接进行对比研究,发现,不同的大脑存在不同的差异,但是这种差异与性别无关,仅6%的大脑区域表现为绝对的“男性”和“女性”。

这份研究认为大脑几乎不存在性别差异,内部一致性与之前关于存在男性大脑和女性大脑的结论相悖。研究成果于11月30日发表于美国国家科学院院刊(PNAS)期刊。


如何看待大脑差异?受性别、遗传、环境等因素影响

研究人员在文章中强调,应避免对整个大脑进行分类,而应该针对特定的大脑区域再进行男性和女性分类。例如,一个女人的大脑拥有一个又大又深的边缘系统(通常与女性有关),同时也有一个一个大体积的顶下叶(主导数字功能的脑区域,通常与男性有关)。

研究人员表明,男性化大脑和女性化大脑是针对大脑不同区域存在的差异特性。而且,这种差异不仅仅受性别因素的影响,还受到环境和遗传因素的影响。研究人员表示,我们应该转变大脑分为两个类别的传统思维。

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