Consciousness helps us learn quickly in a changing world

To understand human consciousness, we need to know why it exists in the first place. New experimental evidence suggests it may have evolved to help us learn and adapt to changing circumstances far more rapidly and effectively. We used to think consciousness was a uniquely human trait, but neuroscientists now believe we share it with many other animals, including mammals, birds and octopuses. While plants and arguably some animals like jellyfish seem able to respond to the world around them without any conscious awareness, many other animals consciously experience and perceive their environment. In the 19th century, Thomas Henry Huxley and others argued that such consciousness is an "epiphenomenon" – a side effect of the workings of the brain that has no causal influence, the way a steam whistle has no effect on the way a steam engine works.