Optimism in pigs

Can you ask a pig if his glass is half full?

Quite a charming bit of research here:

In an experiment reminiscent of Pavlov's dogs, the Newcastle team taught the pigs to associate a note on a glockenspiel with a treat -- an apple -- and a dog training 'clicker' with something unpleasant -- in this case rustling a plastic bag.

The next step was to place half the pigs in an enriched environment -- more space, freedom to roam in straw and play with 'pig' toys -- while the other half were placed in a smaller, boring environment- no straw and only one non-interactive toy.

The team then played an ambiguous noise -- a squeak -- and studied how the pigs responded. Dr Douglas said the results were compelling.

"We found that almost without exception, the pigs in the enriched environment were optimistic about what this new noise could mean and approached expecting to get the treat," she said. "In contrast, the pigs in the boring environment were pessimistic about this new strange noise and, fearing it might be the mildly unpleasant plastic bag, did not approach for a treat.