11 Jan 2009
Nature recently had a series of articles at the interface between science and society which considered the question: What does it mean to be human? Wired asked a similar question a few months ago. Well, there is an old saying “to err is human”. This sets us apart from machines, but we share this tendency with other animals. What sets us apart from other animals who only care about food (self-maintenance) and sex (self-reproduction) ?
Again a self-* property: humans are self-conscious and self-defined. They define themselves over an invented and self-defined name. And every man is expected to become aware of himself through self-consciousness, to find his place in life himself with the help of ‘free-will’, and to create himself as a person.
The key evolutionary innovation was certainly language. Humans are able to understand language which can be used to pass on cultural information very efficiently. They are able to solve a captcha. And only they deal with all the cultural things useless for direct survival and reproduction, for example music, art, and poetry, which belong to other evolutionary systems, systems where information is not transmitted genetically. Humans live in multiple worlds.
To be human means to be stuck in a body closely related to one of the great apes, while being able to understand Shakespeare, to appreciate a Sonata from Beethoven, to laugh about a Charlie Chaplin film, or to build a Large Hadron Collider.
We are located somewhere between genetic and cultural evolution. Our bodies belong to the biological world, our thoughts belong to the cultural word, and our selves are in between. The idea of the self, self-consciousness and language serve as a connection between both worlds and lead to prototypes of religion.
Being human means typically to deal with:
- Self-Consciousness /the ability to recognize yourself/. All animals are selfish survival machines following the needs for self-maintenance and self-reproduction, but only humans experience self-consciousness. Only we can ask, “what am I? I am this? What is this place? And how am I related to it?”
- Language /the ability to communicate/. All animals communicate in one way or another with members of their species, but only humans can describe their environment in detail with language
- Religion /the ability to believe/. Many other animals form groups, too, but only humans recognize and believe that these groups can live longer than any individual. Only humans belief that they have a soul and that groups have a spirit. Only they can form social relations with non-physical agents, fictional characters, and imaginary friends
- Tools /the ability to use objects and tools/ Art and Music /creativity and the desire for beauty/ Stone tools belong to the earliest evidence of human culture, besides pre-historic art and cave paintings.
- Humor /the ability to understand complex inconsistent situations and to produce incongruous actions/. Some animals like hyena make sounds similar to laughter, but only humans laugh if they have understand a funny situation. Laughter separates the human from the animal. Already Kant said “Ein Mensch ist ein thier, das lacht” (a human is an animal which laughs) and Aristotle observed that “only the human animal laughs”.
All of these items are associated with complex cognitive activities and more or less abstract thoughts. The weird, the funny, and the divine belong to abstract thoughts which do not match physical objects directly. Humans as complex BDI-machines with extreme high capacity are capable of abstraction in all three areas: beliefs, desires and intentions. Actions are extended by intentions, perceptions by beliefs, and feelings by desires. Our cognitive system has produced the following emergent properties due to an increased brain:
- sophisticated beliefs and abstract perceptions: language understanding, music and art comprehension, religious thoughts, hope
- sophisticated intentions and abstract actions: language production, music and art production, tool use
- sophisticated desires and abstract feelings: love, sorrow, solidarity, generosity, hate, hostility, humor