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C

The baby monkey is much more developed at brith than the human baby. Almost from the moment it is born,the baby monkey can move around and hold tightly to its mother. During the first few days of its life the baby will approach and hold onto almost any large,warm, and soft object in its environment , particularly if that object also gives it milk. After a week or so , however, the baby monkey begins to avoid newcomers and focuses its attentions on “mother”---the real mother or the mother-substitute(母亲代替物).

During the first two weeks of its life warmth is perhaps the most important psychological(心理的)thing that a monkey mother has to give to its baby. The Harlows, a couple who are both psychologists, discovered this fact by offering baby monkeys a choice fo two types of mother-substitutes ---one covered with cloth and one make of bare wire. IF the two artificial mothers were both the same temperature, the little monkeys always preferred the cloth mother. However, if the wire model was heated, while the cloth model was cool, for the first two weeks after brith the baby monkeys picked the warm wire mother-substitutes as their favorites. Thereafter they switched and spent most of their time on the more comfortable cloth mother.

Why is cloth preferable to bare wire? Sometime that the Harlows called contact(接触)comfort seems to be the answer, and a most powerful influence it is. Baby monkeys spend much of their time rubbing against their mothers’ skins, putting themselves in as close contact with the parent as they can. Whenever the young animal is frightened, disturbed, or annoyed, it typically rushes to its mother and rubs itself against her body. Wire doesn’t “rub”as well as does soft cloth. Prolonged(长时间)”contact comfort” with a cloth mother appears to give the babies confidence and is much more rewarding to them than is either warmth or milk.