A conscious, deliberative “thinking” cycle, drawing heavily on memory, runs through the outer cortex, the region predominantly concerned with punishment and control. An “emotional” circuit, focused on reward and pleasure, operates in the same region, but internally. In their crosstalk, these parallel cycles of perception and action create a balance between the fear of pain or loss and the expectation of pleasure or profit.

The illusion of continuous economic growth and the explosion of credit have thrown that balance out of whack. Thanks to the seductive appeal of today’s consumer economy, perhaps for the first time in human history it is the affirmation of reward rather than the fear of punishment or failure that dominates the calculus of risk. We have become addicted to the quick fix, be that tasty junk food, the electronic cocaine of the Internet, or the painless ease of a credit card purchase.

Research demonstrates that when presented with a choice between a reward now and a greater one after a delay—for instance, $80 today or $100 in two weeks—many of us will opt for the cash in hand, despite its lesser value. Scientists call this temporal discounting. Imaging studies using MRIs show that thinking about an immediate reward lights up the brain’s limbic system, which regulates emotion. Thus passion prevails over reason. That area of the brain is quieter when we’re considering a reward in the distant future, and thus logic wins out. Would you rather have $80 in one year, or $100 in a year plus two weeks? The question answers itself.