A puzzle from ages ago:
What do these things have in common? Nerves, emotions, morality, prices.
They all send signals from distant parts of a coordinating system to a part which makes decisions. The signals are not just information, but costs and benefits to the decision maker so that the decision maker’s interests align with those of the whole. This allows cooperation of larger systems in space and time.
Nerves mean that damage to your toes translates to pain in your mind. This makes your mind act in the interest of your toes (which is of course in the interest of your mind eventually). If your foot is numb your mind is not taking into account the costs and benefits your foot faces, so eventually your foot often becomes injured. Nerves allow larger bodies to coordinate.
Emotions sometimes mean that failure or success of my future self translates to positive or negative feelings now. This makes my current self act in the interests of my future self. If something bad might happen I am scared. If my long term prospects look good I am happy. If your emotions are numb you can make decisions that are bad for your long term wellbeing. Some emotions allow temporally longer humans to coordinate.
Morality means that costs or benefits I cause to others lead to harm or good for me, either in the currency of moral feelings or terms in my calculated decisions (I make no claims here about how people do morality). This is the source of altruism, and of the complaints that it isn’t really altruism. If I donate money to charity I feel good (or calculatedly note that I have increased utility). If I hurt you I feel guilty. If your morality is numb you can hurt other people. Morality allows larger groups of people to coordinate.
Prices are the celebrated example; they mean that the costs and benefits to others across the economy feed into mine when I make choices that affect others. This makes me act efficiently if all goes well. I leave my house if someone else wants it more than I and eat foods that are easier for someone across the world to make. If the farming industry is numb nobody knows when they are doing harm or good regarding it, nor care so much, and we cause dead weight losses. Prices allow even larger groups of people to coordinate.
Can you think of more?