Rebuttal: big cities are what make people crazy.
Citing the work of economist Erzo F. P. Luttmer, who found that support for redistributionist policies was greater among those who live near poor people of the same race, Glaeser argues that “[i]f proximity breeds empathy … then distance may reduce that empathy.”
The problem here is that proximity does not, in fact, breed empathy. It breeds hyperaggression, failure to breed and nurture young normally, infant cannibalism, increased mortality at all ages, and abnormal sexual patterns. Which explains how urban “scientists” can: 1) take from the haves and (after paying themselves handsomely) give to the have-nots, and 2) call such theft “empathy”. It takes a behavioral sink plus higher education to create cannibals who demand congratulations for their diet.
While Glaeser’s argument here remains speculative, it’s in line with a great deal of recent research that suggests wealth (and the attendant ability to segregate oneself from the poor) may make people more selfish and less empathetic.
“Suggests”. “May.” My, what emphatic ambivalence! I was going to go deeper into this idiocy until noticing that Laura at aceofspades already had. So I’ll just note the eternal irony of big-city behaviorists, and get back to my meal.
World's Only Rational Man 
Good post. Ignoring the crud you are rebutting (no, I didn’t go to the link) the “behavioral sink” thing is fascinating. I hadn’t heard of that and I’d like to read up more on it.
I wonder if the causative element in the behavioral sink is the free and unlimited provisions, rather than the limited space per se. In practice, at any rate, humans can adapt. I’m thinking of the high density but high functioning Asian areas, especially Hong Kong:
http://www.chinasmack.com/2012/pictures/hong-kong-high-density-housing-cramped-living-conditions.html
and the now abandoned Gunkanjima (but not abandonded because of social collapse):
http://en.wikipedia.org/wiki/Hashima_Island
(Mrs. Xpat wants to go there–she’s on this concrete ruins kick)
There was also in Hong Kong the famous Kowloon Walled City, which was once notorious for crime (but apparently most folks there just got on with their lives normally):
http://www.dailymail.co.uk/news/article-2139914/A-rare-insight-Kowloon-Walled-City.html
Gunkanjima on Youtube:
Yes, good points. Humans are of course freer to choose their responses than any other (known) creatures, which is why societies vary so much. One of the most astonishing things in my life was learning that Japan has guys whose job is to cram a final few people into subway cars. My jaw almost literally dropped.