Feelgood factor of human interaction | Brief letters

Happy hormones | Fuel costs | Drive-in parking | Guys and girls | Young or old? | Singapore pollution Re your report ( ‘Pull the plug’: protesters resort to direct action against AI firms, 6 October ), the US neuroscientist Ben Rein has shown that there is a fundamental difference in our cognitive response according to the type of interaction we have. In-person meetings and conversations show a dramatic increase in serotonin, oxytocin and dopamine – “feelgood” hormones – compared with online interactions. I have been encouraged to speak to people at bus stops.