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。”