internal motivations. We should note that in reactive behaviours, there might be motivations
that we do not perceive. That is why the borders between the different types of behaviours are
not sharply defined and are fuzzy, but this is not important for our purposes.
We hold that in terms of evolution, first were vegetative behaviours, then reflex, then
reactive, then motivated, then reasoned, and then conscious ones. Reasoned behaviours require
concepts (symbolic representations), and manipulation of those concepts in order to select the
behaviour. Some might not have any differences, for an outside observer, from the previous
ones. But reasoned behaviours require concepts and a logic in the action selection process. So,
in individuals with reasoned behaviours, motivated and reactive behaviours might or might not
be reasoned. But there are plenty of complex reasoned behaviours that require of concepts and
logic in order to be achieved. Extreme examples would be designing a spaceship and the
planning of a perfect murder. We can see that reasoned behaviours require of a language and
a culture, in order to evolve from previous behaviours. Also here the border is fuzzy, because
there can be many different degrees (complexities) of reasoned behaviours. We can say that
conscious behaviours are the ones that are executed while being aware of them, without falling
in the debate of what and where consciousness is. This might be also seen as reasoning about
what we are reasoning (similar to what Dennet calls a second order intentional system (Dennet,
1987)). Reasoned and conscious behaviours imply higher cognition. We can see that the more
evolved types of behaviours are more complex. We also argue that plasticity is increased
through the different levels of behaviours as well. This is, more evolved behaviours adapt
(learn) faster to changes in the environment. More basic behaviours should not be too plastic,
because they are in charge of more vital functions (e.g. if we would need to be conscious of our
breathing, we could forget about it). Figure 1 shows graphically the previous classification.
Figure 1. Organization of different types of behaviours.