Does the brain really create of all our cravings, dreams and desires or is there actually a lot more to it than that?
Hormones have a lot to do with it. Our day-night cycle, our need for specific nutrients, and the urges to perform bodily functions are often caused by hormones in our blood that are created by glands and targeted at our organs.
So do pheromones. Experiments show that, like most mammals, we react to the chemicals in many biological substances, such as tears, even though they don't have an "odor" that we can smell consciously.
The pheromones in a woman's tears arouse feelings of sympathy and protectiveness in most men. And they have to be genuine tears of sadness! The tears that come from laughing too hard or eating too many chili peppers don't contain the pheromones.
Of course most of these inputs are sorted out in our brains and in most cases it's the brain that devises the specific reaction. (Obviously not things like defecation but most other activities are brain-controlled.) But it's fair to say that a significant portion of the stimuli that affect our behavior are actually first processed by other parts of our body, and quite often our
nose.
In case you don't know this, it's very humbling to learn that the entire vertebrate brain is an outgrowth of the original
olfactory lobe! The first fish were guided by the chemicals in the water that led them to food or away from danger.
