from reflex to intelligence

human reflexes are one of the most fascinating and old evolutionary traits

some common ones are: pulling your hand away from accidentally touching something hot or closing your eyes if something comes too close

reflexes are usually responses that bypass the brain, you usually realise a fraction of a second after your body has already saved you. in some cases, the central nervous system has commanded the muscles to move even before the pain signal reaches your brain

the most primitive microorganisms do not have anything akin to a brain, all they have are reflexes - take the discovery of light gated ion channels (and optogentics that won the nobel prize this year) - the green algae this was discovered in survives on this reflex, it senses light and swims in that direction

seeing it simple origins, i always questioned why we need it given we have a hat rack that uses 20% of the oxygen we breathe and blood the heart pumps - why have such a powerful computer and have some functions bypass it completely?

ironically, the answer usually given is speed - our brain is quite slow, the skin burns quickly and if not for reflexes we would all have a lot of serious burns - guaranteed

but the answer i like better is, most organisms are not born with a brain that ready to just go, it needs some learning, some getting used to and for the propagation of life, its very counterproductive if only the organism taught to avoid danger end up surviving

essentially, we are born with reflexes for our survival. the most basic being how to drink milk - you don’t have to teach them - they can barely see or make out what is happening but they inherently know that they need to drink milk to survive

these reflexes develop early in the womb and eventually fade out as the baby grows - when the brain takes over voluntarily

but reflexes are so baked into, patients with dementia for example start showing primitive reflexes again. the palmar grasp reflex is thought to be vestigial remnant from when our ape ancestors had fur and its baby had to instinctively hold onto the fur in order to survive - no longer needed but very much present - although these days its new purpose is to primarily melt your heart when a newborn with its tiny fingers grasps your finger

reflexes are proof that “intelligence” took a very long journey - 4 billion years to develop - much of it from trial and error

as we talk continuously about wanting to redefine intelligence, build it artificially etc - its worth keeping in mind how its namesake actually came about