Cities might literally program your emotional state through collective facial recognition feedback loops.

Peripheral vision processes facial expressions at distance → measurably alters your emotional baseline → you project that state outward → affects next person's peripheral scan → cascading emotional contagion.

If enough nodes in the network carry specific emotional signatures, the entire system tilts. Not just vibes - quantifiable psychological state transfer.

Urban design as emotion engineering? Parks might be intentional circuit breakers in the feedback loop. Greenspace = emotional reset zones to prevent runaway negative cascades.

The studies (PLoS ONE papers on facial emotion detection, peripheral vision processing, and emotional contagion) show this isn't mystical city energy - it's measurable neurological response patterns propagating through dense human networks.

Every face you pass is both input and output in a distributed emotional computation system. Cities are just really dense neural nets running on human wetware.