Meyer J S, Novak M A, Bowman R E, Harlow H F
Dev Psychobiol. 1975 Sep;8(5):425-35. doi: 10.1002/dev.420080507.
Mother-reared and surrogate-peer-reared rhesus monkeys were separated from their respective attachment objects at 6 months of age and tested for the following 9 weeks to determine their home-cage behavior and their pituitary-adrenocortical responses to stress. Both groups displayed a strong immediate behavioral response to separation which was characterized by increased vocalization, increased locomotion, and decreased self-play. However, the surrogate-peer-reared infants showed a subsequent recovery in their levels of self-play whereas the mother-reared infants instead developed stereotypic behavior patterns such as repetitive pacing. The 2 groups displayed similar plasma cortisol responses to weekly sessions in an apparatus equipped with animated toy "monsters". Mother-reared but not surrogate-peer-reared subjects, however, also manifested elevated cortisol levels when an animal in an adjacent cage was captured and removed for stress testing. Mother-reared infant monkeys thus responded in a stronger and more prolonged manner to the loss of their attachment object than surrogate-peer-reared infants. These results suggest that infant rhesus monkeys form stronger attachments to monkey mothers than to inanimate surrogate mothers, a phenomenon which has not been as clearly demonstrated using other indices of attachment strength.
由母亲抚养和由代孕同伴抚养的恒河猴在6个月大时与各自的依恋对象分离，并在接下来的9周内接受测试，以确定它们在笼中的行为以及垂体-肾上腺皮质对应激的反应。两组在分离时都表现出强烈的即时行为反应，其特征是发声增加、活动增加和自我玩耍减少。然而，由代孕同伴抚养的婴儿随后自我玩耍水平有所恢复，而由母亲抚养的婴儿则出现了刻板行为模式，如重复踱步。在配备有动画玩具“怪物”的装置中，两组对每周的测试表现出相似的血浆皮质醇反应。然而，当相邻笼中的一只动物被捕获并带走进行应激测试时，由母亲抚养而非由代孕同伴抚养的受试者也表现出皮质醇水平升高。因此，与由代孕同伴抚养的婴儿相比，由母亲抚养的婴儿猴子对其依恋对象的丧失反应更强烈、更持久。这些结果表明，恒河猴婴儿对猴妈妈形成的依恋比对无生命的代孕妈妈更强，这一现象用其他依恋强度指标尚未得到如此清晰的证明。
