Of chemicals and competition

Your article on the relatively low sperm counts of rural men (“Looking for a Geographic Pattern to Sperm Counts,” Jan. 13), compared with those in big cities, says that the scientists in the reported study had hypothesized that agricultural chemicals might be depressing male sperm counts.

But maybe it’s the other way around. Maybe the urban counts are elevated. Evolutionary psychologists might want to examine whether increasing population density -- more males competing for females -- somehow triggers a biochemical reaction.

That’s what New York always felt like to me.

Jonathan D. Kaufelt

Santa Monica