Then the scientists threaded the rope so that it would take two elephants, pulling both ends at the same time, to move the table. If one yanked an end without its helpmate doing so, no reward.
Pulling the single rope would produce the identical food reward, but only with the help of another child or chimp in the room next door, who had to pull the opposite end of the rope at the same time.
只有在另一个孩子或者猩猩的帮助下，同时朝着绳子反方向的一端拉，才能得到相同的食物。
3
A church bell usually resides in a steeple and the exercise involved has to do with repeatedly pulling on a rope.