We can not see the behavior that happens in the brain from the outside (researchers consider mental processes such as thinking and feeling also as “behavior”, i.e., something that the body does, only that we can not see it from the outside). Through language and other symbols, we humans can tell each other about our inner experience. But how can we then find out what other animals think and feel, and whether they have similar thoughts or ideas, as we humans do?

Using modern research methods, such as functional magnetic resonance imaging (fMRI), we can at least observe the activity of nerve cells in the brain while organisms do certain things – which brain regions are active how strongly, how are they interconnected? And how does brain activity differ between humans and other species while they are doing similar things?

Another method that scientists use to compare the mental faculties of humans and other species is to observe behaviors while performing certain tasks. If, for example, chimpanzees or small children can remember something from yesterday or think about tomorrow, then they would need to be able to solve a particular task that requires that mental ability – e.g. pick up a tool or save food for later, because they may need it then.

However, we can also easily observe and “explore” our own minds without much effort or fancy technology: what different things does our mind actually do? And why does it do these different things? Which of these different things do we share with other animals, and which not? With which do we come into the world, and which only develop in the course of our life?

Scientists have come up with various metaphors and analogies to describe and differentiate the different behaviors in our mind. For example,

• “Fast Thinking”, “Slow Thinking”
• “Moral Taste Buds”
• “Mental Time Travel”
• the “Noticer”, the “Discoverer”, and the “Advisor”