What do you think you are?: Part one

There is growing scientific evidence that many animals are not only conscious, but possess a more profound sense of self. They can learn by experience and make decisions that depend on a sense of the future - in other words, they are “sentient” beings with the capacity to feel pain, pleasure and emotions. Sue Armstrong reports on the latest scientific research into the minds and consciousness of animals of all sorts, from chimpanzees to birds, bees and cuttlefish.