Riding home on Fountain Avenue after a full afternoon of cruising around, a man in a white SUV honks his horn behind my rear wheel. The road is sufficiently narrow so as not to allow both a bicycle and a SUV to pass at least for another block. When traffic clears in the opposing lane, he speeds past me slowing down just enough to audibly yell, “Get out of the fucking way.” I yell something incoherent back which prompts him to slow down to engage in a heated exchange. I ask him why he needs to go so fast when there was a red
light ahead---a logical conjecture based on given visual stimulus. To which he retorts, “I will fucking run you over, you little faggot!” He speeds on ahead only to be stopped by the red light.

Aggression in the male is caused by several factors and biochemical exchanges in the brain. There is substantial evidence to suggest that aggressive behavior is largely genetically determined. This is due, in part, to genes producing elevated testosterone and lower serotonin levels which encourage impulsive behavior associated with aggression--in this case, malicious verbal aggression.

The SUV driver, prior to our verbal exchange, was probably overwhelmed with the stress of not being able to overcome this simple obstacle. His head had been clouded with years of commercials promising his SUV would be able to bulldoze over mountain terrain—suspension and paint job intact. He and his powerhouse, gas-guzzling machine were trapped on an urban street stalled by a less-expensive, more efficient form of locomotion. He was definitely not scaling rugged rock formations or parting shallow stream beds.

His stress signaled an immediate reaction from his mid brain--the source of automatic, primitive cognitive reactions. He did not consider the red-light visual
stimulus, as I had, to allow upper cortical processing to occur. His immediate reaction was rewarded by a release of dopamine in his hypothalamus. The aggressive action he exhibited probably satisfied the immediate need to avoid the stress of a bicycle (i.e., it made him feel better) but was futile in comparison to the overall late-afternoon traffic that would allow me to continue
ahead steadily as he stuttered through the streets.