Wednesday, March 30, 2011

Two faces of the gambling habit

A variable ratio reinforcement schedule is one that generates gambling behaviour. In such a schedule – commonly used on pigeons in psychology laboratories – a pigeon is reinforced with some kind of food pellet after it presses a panel. But it does not get a reward every time it presses. Rather, it may get a reward after the 10th press and the 12th press, with nothing happening for the next 80 presses, after which it may get a reward for the 81st press, and so one. In brief, the pigeon is rewarded unpredictably. Such a reinforcement schedule generates very high response rates. It is very similar to what happens in gambling – where one (unpredictable) response is enough to pave the way for an uncontrollable gambling habit, even in spite of the common knowledge that the chances of winning are very slim.

There is the obverse to this, too, and a hilarious but true article by Henry Farrell, in response to an article by Alan Greenspan in yesterday’s Financial Times, captures it nicely. This exemplifies how we are often lulled into a sense of security where there is no room for it, because the accident that is waiting to happen has not happened, even when we are aware that such an accident may happen (just as the gambler knows that winning is an accident and that he will ultimately lose). Greenspan’s article contains the following :

Today’s competitive markets, whether we seek to recognize it or not, are driven by an international version of Adam Smith’s “invisible hand” that is irredeemably opaque. With notably rare exceptions (2008, for example), the global “invisible hand” has created relatively stable exchange rates, interest rates, prices, and wage rates.”

Farrel goes on to enumerate some “rare exceptions”:

"With notably rare exceptions, Japanese nuclear reactors have been secure from earthquakes.
Though unredeemably(sic) opaque, Mr. Madoff’s operations delivered excellent returns, with notably rare exceptions.
With notably rare exceptions, the levees protecting New Orleans have held fast in the face of major hurricanes.
With notably rare exceptions, locking all exits to the workplace is a harmless way to improve your employees’ productivity.
With notably rare exceptions, petroleum extraction has minimal environmental impact."

To which I may add that, with notably rare exceptions, planes are able to land and take off at London Heathrow Airport, which has just been voted 99th in a list of airports.

All of which makes me wonder whether the neurobiology underlying the gambling behaviour in fixed-ratio reinforcement schedules is not very similar to the neurobiology underlying the – what should I call it ? – negative variable ratio reinforcement!!