That stress, and stress alone, is responsible for damaging the working memories of poor children thus looks like a strong hypothesis. It is also backed up by work done on both people and laboratory animals, which shows that stress changes the activity of neurotransmitters, the chemicals that carry signals from one nerve cell to another in the brain. Stress also suppresses the generation of new nerve cells in the brain, and causes the "remodelling" of existing ones. Most significantly of all, it shrinks the volume of the prefrontal cortex and the hippocampus. These are the parts of the brain most closely associated with working memory。
   

　　压力，只有紧张的压力，才对贫困儿童工作记忆体的损害负有责任。这看似一个强有力的前提。同时也在对人研究和实验动物两个方面得到了验证。这表明，压力会改变神经递质的化学特性，即影响信号从一个神经细胞到另一个神经细胞的传递。还会抑制新的神经细胞在大脑中的产生，并导致现有大脑的“重塑”。最为明显的是，它缩小了前额叶皮质和海马体的体积。而这些地区恰恰与大脑的工作记忆密切相关。

　　Children with stressed lives, then, find it harder to learn. Put pejoratively, they are stupider. It is not surprising that they do less well at school, end up poor as adults and often visit the same circumstances on their own children。

　　这些面对生活压力的儿童，学习往往不佳，被人看不起，被当成笨人。所以他们在学校表现差，长大成人后会变为穷人也就不足为奇了，而他们的子女会遭遇到相同的境况。

　　Dr Evans's and Dr Schamberg's study does not examine the nature of the stress that the children of the poor are exposed to, but it is now well established that poor adults live stressful lives, and not just for the obvious reason that poverty brings uncertainty about the future. The main reason poor people are stressed is that they are at the bottom of the social heap as well as the financial one。

　　埃文斯博士和尚博格博士的研究没有涉及贫困儿童面临压力的性质，但有一点是确定的，即成年人的贫困生活，会导致未来的不确定性。穷人处于社会地位和经济状况的最底层，这是压力的主要原因。

　　The Bible says, "the poor you will always have with you".  Dr Evans and Dr Schamberg may have provided an important part of the explanation why。

　　圣经说， “穷人，你将常伴穷困 ”。也许，埃文斯博士和尚博格博士为此提供了一个重要的解释。