Well, you know, that was the worst of it - this suspicion of their not being inhuman. It would come slowly to one. They howled, and leaped, and spun, and made horrid faces; but what thrilled you was just the thought of their humanity - like yours - the thought of your remote kinship with this wild and passionate uproar.

In this exert, Marlow has a hard time comeing to grip with the similarity between him and the wild tribal men. He discovers that being that start out so similar can become so very different depending upon the surrounding in which they are raised.