Seems like it could be as simple as the pollution. The pictures simulate the same experience. For instance, if colleges students subliminally read words about old people, they'll walk slower.
Breathing car exhaust can't be good. Carbon monoxide is known to slow actions. Different urban environments are also more likely to have poor conditions (e.g., lead exposure) that leads to brain damage (smaller frontal lobes) and criminality (less rational decisions):
Breathing car exhaust can't be good. Carbon monoxide is known to slow actions. Different urban environments are also more likely to have poor conditions (e.g., lead exposure) that leads to brain damage (smaller frontal lobes) and criminality (less rational decisions):
http://medicine.plosjournals.org/perlserv/?request=get-docum...