[00:11.27]Everybody loves a fat pay rise.
[00:14.10]Yet pleasure at your own can vanish if you learn
[00:17.22]that a colleague has been given a bigger one.
[00:20.43]Indeed, if he has a reputation for slacking,
[00:24.06]you might even be outraged.
[00:26.69]Such behaviour is regarded as "all too human",
[00:30.64]with the underlying assumption that other animals
[00:33.44]would not be capable of this finely developed sense of grievance.
[00:37.99]But a study by Sarah Brosnan
[00:40.10]and Frans de Waal of Emory University in Atlanta, Georgia,
[00:44.72]which has just been published in Nature,
[00:47.56]suggests that it is all too monkey, as well.
[00:52.10]The researchers studied the behaviour of female
[00:55.22]brown capuchin monkeys.
[00:57.95]They look cute.
[00:59.24]They are good-natured, co-operative creatures,
[01:02.17]and they share their food readily.
[01:04.80]Above all, like their female human counterparts,
[01:08.62]they tend to pay much closer attention to
[01:11.36]the value of "goods and services" than males.
[01:15.90]Such characteristics make them perfect candidates
[01:19.01]for Dr. Brosnan's and Dr. de Waal's study.
[01:23.38]The researchers spent two years teaching their monkeys
[01:26.89]to exchange tokens for food.
[01:30.32]Normally, the monkeys were happy enough
[01:32.84]to exchange pieces of rock for slices of cucumber.
[01:37.48]However, when two monkeys
[01:39.21]were placed in separate but adjoining chambers,
[01:42.75]so that each could observe
[01:44.25]what the other was getting in return for its rock,
[01:47.47]their behaviour became markedly different.
[01:51.40]In the world of capuchins,
[01:53.31]grapes are luxury goods (and much preferable to cucumbers).
[01:58.35]So when one monkey was handed a grape
[02:00.89]in exchange for her token,
[02:02.80]the second was reluctant to hand hers over
[02:05.74]for a mere piece of cucumber.
[02:07.95]And if one received a grape without
[02:09.85]having to provide her token in exchange at all,
[02:13.68]the other either tossed her own token
[02:16.40]at the researcher or out of the chamber,
[02:19.52]or refused to accept the slice of cucumber.
[02:23.45]Indeed, the mere presence of a grape in
[02:26.07]the other chamber (without an actual monkey to eat it)
[02:30.12]was enough to induce resentment in a female capuchin.
[02:34.56]The researchers suggest that capuchin monkeys,
[02:37.79]like humans, are guided by social emotions.
[02:41.62]In the wild, they are a co-operative, group-living species.
[02:45.67]Such cooperation is likely to be stable only
[02:49.10]when each animal feels it is not being cheated.
[02:52.84]Feelings of righteous indignation, it seems,
[02:55.54]are not the preserve of people alone.
[02:58.57]Refusing a lesser reward completely makes
[03:01.39]these feelings abundantly clear
[03:03.21]to other members of the group.
[03:06.84]However, whether such a sense of fairness
[03:09.86]evolved independently in capuchins and humans,
[03:13.49]or whether it stems from the common ancestor
[03:16.13]that the species had 35 million years ago,
[03:19.56]is, as yet, an unanswered question.内容来自 听力课堂网：http://www.tingclass.net/show-8686-251455-1.html