题目

Chimps(黑猩猩) will cooperate in certain ways, like gathering in war parties to protect their territory. But beyond the minimum requirements as social beings, they have little instinct (本能) to help one another. Chimps in the wild seek food for themselves. Even chimp mothers regularly decline to share food with their children. Who are able from a young age to gather their own food.In the laboratory, chimps don’t naturally share food either. If a chimp is put in a cage where he can pull in one plate of food for himself or, with no great effort, a plate that also provides food for a neig在○里填上“＞”、“＜”或“=” 300秒○6分