人脑与其他动物脑子不同的最基本的原因就是因为人脑是世界上最复杂的东西。通过口头和笔头语言进行交流的能力是一个重要特征。在人脑中，(控制)语言和思想的中枢要远远更为发达。

Like food and houses, clothing is a basic human need. One reason people began wearing clothing was for protection. In ancient times, rough garments protected our ancestors from animal bites and kept them from being hurt. Clothing also kept them warm and dry.
    Today clothing is also worn for reasons other than protection against the weather. One of the most important reasons is appearance. People choose clothes in styles and color that they like and that they think other people will like.

The human brain differs from the brains of other animals for one very simple reason—it is by far the most complex thing in the world. The ability to communicate through spoken or written language is an important feature. In human brains the centers for language and thought are far more developed.
    While your brain accounts for only about two percent of your body weight, it takes 20 percent of your body’s oxygen supply and uses up 20 to 30 percent of your body’s energy.