猪会根据待遇表现乐观与悲观

　　Half of the pigs were then placed in an enriched environment –more space, straw and toys – while the others were put in a smaller, boring pen.

　　一半猪被放在良好的的环境下，有更多空间，稻草和玩具。而另一半猪则被放在狭小又吵闹的空间。

　　The team then played an ambiguous noise – a squeak – and studied how the pigs responded.

　　研究组把这些猪被放在一种嘈杂环境中，并研究这些猪会作何反应。

　　Dr Douglas said: ‘The pigs in the enriched environment were optimistic about new noise and approached. "

　　道格拉斯博士说：“在良好环境下的猪更加愿意接受新的噪音，”

　　‘The pigs in the boring environment were pessimistic and, fearing it might be the bag, did not approach for a treat.

　　“而在不好环境中的猪则更加悲观，以为这种声音可能是要来猎捕他们的声音，并不会把这当做一种乐趣。”