Stay the Course?
Persistence is a topic of folk wisdom and behavioral science. Admiral Farragut’s “Damn the torpedoes; full speed ahead!” or sayings like “Never say die” all point to staying the course, even when it’s rough. Behavioral psychologists have, for a very long time, been interested in the circumstances under which behavior does or does not persist. Our recently deceased outstanding colleague Tony Nevin began investigating these circumstances in the mid-1970s, and by the 1990s, his research had expanded into applied settings for obvious reasons. Persistence, or lack thereof, remains today a significant topic of research, although the variables responsible for it are far from determined.
Now, staying the course can be a good or a bad thing. The persistence of self-defeating behavior is the fodder of novels, films, and poetry, not to mention the primary focus of both traditional and behavioral psychological interventions. Staying the course in the case of substance addiction is the pits for everyone concerned. On the positive side, the persistence of such positive behavior as that associated with weight management, exercise, healthy eating, and prosocial interactions has received considerable attention in both laboratory and real-life settings.
One particularly interesting problem related to this general topic of persistence is that of staying the course when the point of diminishing returns has been reached. Examples abound. It is difficult for many couples to break their bonds even when it is obvious to the rest of the world that the breakup is long overdue because neither member of the dyad is getting out of it what each wants. 
And so, it continues. Having invested a small fortune in a start-up without it paying off, the investor continues to pour her hard-earned money into the enterprise, even though any objective assessment of the enterprise’s chances of success is screaming “STOP!” Or, the new homeowners, having invested heavily in the purchase of their new house, continue to spend money on its renovation, pushing their investment far beyond their abode’s value.
As parents, we often do the same thing with our kids. It often isn’t enough to expose our tykes to a little baseball or a little dance just to introduce them to such activities. For many people, a little involvement suddenly snowballs to the point that parents and tykes are swept into a tornado of increasing involvement from which there seems no escape.
sunk cost effect | "The idea that a company or organization is more likely to continue with a project if they have already invested a lot of money, time, or effort in it, even when continuing is not the best thing to do." All of these examples illustrate something called the “sunk cost effect,” which also can be restated proverbially as ‘in for a dime, in for a dollar.' Although there has been a little behavioral research on the topic, it remains one of those pervasive issues with tons of implications for applying our science to the daily concerns of people. A few years ago, Edmund Fantino and some of his students wrote a little about the sunk cost in laboratory settings, and Edmund also has considered some of its implications for everyday life. The need for further experimental analysis of sunk cost phenomena—the dark side of persistence—is almost palpable.
