科学家发现，狗能感到一种简单形式的嫉妒。对不同物种的实验表明当一只猴子的伙伴因为执行完全一样的任务却接受了更多奖赏的时候，它常常表达出怨恨的行为。猴子表现出进行罢工、拒绝参与以及忽略它们所认为的较低级别的补偿。
Friederike Range及其同事报告说，狗也具有类似的辨别能力，尽管敏感度较低。这组科学家对由其主人陪同的一对家养的狗进行了实验。受试狗和它的伙伴相邻坐着，而它们的主人站在它们的身后，每一只狗被提示把爪子放在实验者的手上，如果它这样照办了，它将会得到一片香肠或者面包。和多种对照情况相比，这些狗对于不公平的奖赏分配的反应不同，这是根据当受试狗的伙伴因为完成任务而获得食物但受试狗没有得到食物时的反应而衡量的。这种怨恨可以用实验者提示狗的次数或者狗在拒绝之前执行任务的次数量化。这些狗看上去并不关心究竟它们得到了什么奖赏，也不关心伙伴在收到食物前是否完成了任务。这组科学家说，狗的嫉妒可能是更复杂的灵长类感情的进化前驱。（生物谷Bioon.com）
生物谷推荐原始出处：
PNAS December 8, 2008, doi: 10.1073/pnas.0810957105
The absence of reward induces inequity aversion in dogs
Friederike Rangea,b,1, Lisa Horna, Zsófia Viranyib,c, and Ludwig Hubera
aDepartment of Neurobiology and Cognition Research, University of Vienna, A-1091 Wien, Austria;
cKonrad Lorenz Institute for Evolution and Cognition Research, A-3422 Altenberg, Austria; and
bWolf Science Center, 4645 Grünau, Austria
Abstract
One crucial element for the evolution of cooperation may be the sensitivity to others' efforts and payoffs compared with one's own costs and gains. Inequity aversion is thought to be the driving force behind unselfish motivated punishment in humans constituting a powerful device for the enforcement of cooperation. Recent research indicates that non-human primates refuse to participate in cooperative problem-solving tasks if they witness a conspecific obtaining a more attractive reward for the same effort. However, little is known about non-primate species, although inequity aversion may also be expected in other cooperative species. Here, we investigated whether domestic dogs show sensitivity toward the inequity of rewards received for giving the paw to an experimenter on command in pairs of dogs. We found differences in dogs tested without food reward in the presence of a rewarded partner compared with both a baseline condition (both partners rewarded) and an asocial control situation (no reward, no partner), indicating that the presence of a rewarded partner matters. Furthermore, we showed that it was not the presence of the second dog but the fact that the partner received the food that was responsible for the change in the subjects' behavior. In contrast to primate studies, dogs did not react to differences in the quality of food or effort. Our results suggest that species other than primates show at least a primitive version of inequity aversion, which may be a precursor of a more sophisticated sensitivity to efforts and payoffs of joint interactions.
