我们知道，有些小狗在经过训练之后会做算术题。难道狗真的能够计算吗？让奥地利生物学家、诺贝尔奖金获得者Konrad Lorenz告诉我们答案吧：
At first sight, their performances are really astounding. You are invited to set the examination yourself and you are put opposite the horse, terrier or whatever animal it is. You ask, how much is twice two; the terrier scrutinizes you intently and barks four times. In a horse, the feat seems still more prodigious for he does not even look at you. In dogs, who watch the examiner closely, it is obvious that their attention is concentrated upon the latter and not, by any means, on the problem itself. But the horse has no need to turn his eyes towards the examiner since, even in a direction in which the animal is not directly focusing, it can see, by indirect vision, the minutest movement. And it is you yourself who betray, involuntarily to the ‘thinking’ animal, the right solution. Should one not know the right answer oneself, the poor animal would knock or bark on desperately, waiting in vain for the sign which would tell him to stop. As a rule, this sign is forthcoming, since few people are capable, even with the utmost self-control, of withholding an unconscious and involuntary signal.
原来，狗或马在某些方面的感觉比人类要灵敏得多，通过观察测试者，就能察觉其不自觉间流露出的信息——问题的答案。当你向小狗提出算术题时，它会直勾勾地盯着你，注意力完全集中在研究你的表情、动作上，而不是集中在问题本身上。马的感觉更加敏锐：它甚至用不着直接盯着你，用余光瞟一眼就能察觉最细微的动作。而对于绝大多数人来说，不论自制力有多强，总会在不知不觉间流露出某种信息，泄漏了问题的答案。