In the 1990s, a research team in Parma led by Giacomo Rizzolatti discovered something strange while studying macaque monkeys. Neurons that fired when a monkey reached for food also fired when the monkey watched another monkey reach for food. The same cells. Same firing pattern. Just observation.
They called them mirror neurons. Subsequent research suggested humans have a far more elaborate version of the same system.
What this means: when you watch someone in pain, your brain runs a partial simulation of that pain. When you see someone smile, your motor cortex lights up in the pattern of smiling. You don’t just see other people. On some level, you briefly become them.
This has been debated, refined, partially walked back by researchers worried about overclaiming. The basic phenomenon holds: human brains are built to resonate with other human brains. We are, neurologically, more continuous with each other than we typically assume.
The mystery traditions had a word for this: sympathy. Not in the modern sense — in the older sense of things vibrating together, sharing a frequency. The alchemical texts are full of it. The idea that like calls to like, that resonance is a fundamental property of reality, that the boundary between self and other is more permeable than it looks.
Neuroscience got there eventually, by a different route.
What I find interesting is what this suggests about connection. If you’re partially simulating the interior states of the people around you, then your emotional environment isn’t just influenced by who’s in the room — it’s partly constructed from them.
The Stoics understood this practically, even without the neuroscience. Epictetus was very clear about the importance of choosing carefully who you spend time with. Not as snobbery — as hygiene. Spend enough time with someone’s patterns and you start running them yourself.
You are, to a degree most people find uncomfortable, made of other people. The self that feels so singular and interior is porous at the edges.
This is alarming and beautiful in about equal measure.