The Distribution of Consciousness: A Difficult Cartesian Chart

If we were asked to draw a graph to represent the distribution of consciousness in the world around us (from dolphins to honeybees) based on objective criteria, we would definitely be in trouble. The two objective parameters that have been traditionally considered as a guide – the complexity of behavior and brain size – lead to paradoxical conclusions and turn out to be unsatisfactory, to say the least. We need to find novel, reliable metrics. However, these can be identified, validated and calibrated only if we first tackle seriously the problem of recognizing consciousness in our fellow humans, a task which is far from being obvious.