The Umwelt

Yesterday I was out in the yard with my cat, and watched her lift her nose to the wind. She was reading the scents of our neighborhood in a way I am completely incapable of. Often times I have seen her sniff at a bush and wished she could tell me the story of who passed by in the night. I sniff the bush and I don’t smell anything.

I see my neighbor’s dog prick up his ears: he hears something that is totally beyond my hearing. What does he know that I don’t know?

There is a world of sense experience all around me that these animals smell and hear but I am completely unaware of. What else might be right here under my nose that I can’t sense? I think I perceive all of reality as it is, but my cat and the dog show me I don’t.

A century ago a German biologist noticed this disparity in sense perception and came up with a term for an organism’s personal reality: the umwelt.

Neuroscientist David Eagleman writes about this idea in his new book, Incognito:

What you are able to experience is completely limited by your biology. This differs from the commonsense view that our eyes, ears, and fingers passively receive an objective physical world outside ourselves. As science marches forward with machines that can see what we can’t, it has become clear that our brains sample just a small bit of the surrounding physical world.

In 1909, the Baltic German biologist Jacob von Uexküll began to notice that different animals in the same ecosystem pick up on different signals from their environment. In the blind and deaf world of the tick, the important signals are temperature and the odor of butyric acid. For the black ghost knifefish, it’s electrical fields. For the echolocating bat, air-compression waves. So von Uexküll introduced a new concept: the part that you are able to see is known as the umwelt (the environment, or surrounding world), and the bigger reality (if there is such a thing) is known as the umgebung. Each organism has its own umwelt, which it presumably assumes to be the entire objective reality ‘out there.’ Why would we ever stop to think that there is more beyond what we can sense?

The film The Truman Show is a perfect example of someone confusing his umwelt with the umgebung. Truman is raised in a giant bubble, an invented world of actors, every moment of his life filmed for the ultimate reality TV show. But Truman believes his world is reality, not a fake—it’s all he’s ever known. What could ever make him question it? Eventually he starts noticing flaws, and the film documents his slow realization that his world is, in fact, not reality. We cheer Truman’s heroic effort to break through the limits of his umwelt into the larger reality.

Dr. Eagleman quotes an interviewer asking the film’s director, “Why do you think Truman has never come close to discovering the true nature of his world?” The director replies, “We accept the reality of the world with which we’re presented.”

The pertinent aspect of this concept in this context is that humans believe they are in touch with reality. We think our subjective reality is reality. The definition of insanity in this blog is “confusing our subjective opinion with objective fact.” When I sit on my porch and think I am experiencing reality I am delusional; I am only experiencing my umwelt. Recognizing this allows me to experience humility: I am aware of how little I know in any situation. My knowledge will always be limited.

Just admitting that my personal subjective reality is limited opens me up to be able to  experience more of what is out there.

If you’re interested in hearing more about the tick’s umwelt, here’s a discussion of it from Wikipedia:

The umwelt is for [Jakob von Uexküll] an environment-world which is (according to Agamben), "constituted by a more or less broad series of elements [called] "carriers of significance" or "marks" which are the only things that interest the animal". Agamben goes on to paraphrase one example from Uexküll's discussion of a tick, saying,

"...this eyeless animal finds the way to her watchpoint [at the top of a tall blade of grass] with the help of only its skin’s general sensitivity to light. The approach of her prey becomes apparent to this blind and deaf bandit only through her sense of smell. The odor of butyric acid, which emanates from the sebaceous follicles of all mammals, works on the tick as a signal that causes her to abandon her post (on top of the blade of grass/bush) and fall blindly downward toward her prey. If she is fortunate enough to fall on something warm (which she perceives by means of an organ sensible to a precise temperature) then she has attained her prey, the warm-blooded animal, and thereafter needs only the help of her sense of touch to find the least hairy spot possible and embed herself up to her head in the cutaneous tissue of her prey. She can now slowly suck up a stream of warm blood."

Thus, for the tick, the umwelt is reduced to only three (biosemiotic) carriers of significance: (1) The odor of butyric acid, which emanates from the sebaceous follicles of all mammals, (2) The temperature of 37 degrees celsius (corresponding to the blood of all mammals), (3) The hairy topography of mammals.