Why Behavior Overshadows Statistics

If we’re sick or injured, we’re generally not satisfied with an explanation such as “These things just happen sometimes.”

A number of psychological studies suggest that we are more liable to attribute the occurrence of an unfortunate event to people rather than to chance, particularly if it is dramatic or has emotional implications.

In one study by psychologist Ed Walster, a group of subjects was told that a man parked his car on an incline and that it rolled down into a fire hydrant after he walked away. Most of the group expressed tolerance and said they had had similar lapses.

Another group was told a slightly altered story in which the car rolled into a pedestrian after the driver walked away. The members of this second group were much more critical of the man’s actions, vilified him, and tended to hold him responsible even though the negligence was the same in both stories.

If things go seriously wrong, we’re predisposed to go looking for someone responsible.

Firestone Tires

Such studies bring to mind dramatic accusations in recent news stories and, in particular, of alleged executive wrongdoing in the Firestone-Ford case. First, let’s note the statistics behind the tire story. The New York Times made the statistical basis of the complaint against Firestone much clearer when it noted that fatal crashes of Ford Explorers, which use Firestone tires, were almost 2.8 times as likely to involve faulty tires as fatal crashes of other sports utility vehicles.

Other ways of looking at the data — and there are many — did not point to any problem with the tires.

This shouldn’t be that surprising for two reasons. First, relationships among variables buried in mountains of data are often hard to find (although, given enough time, data-mining techniques can turn up all sorts of interesting ones, including many that are bogus).

The second reason is the rarity of the crashes. Despite the extensive coverage, which probably suggests to many that treads have been flying off tires left and right, there was, on average, one tire-related fatal crash of a Ford Explorer per 3 billion miles driven. About 100 of the roughly 160,000 automobile deaths during the years 1995 to 1998 were due to faulty tires. In contrast, about 80,000 of the 160,000 automobile deaths during these years involved alcohol. Even driving a lighter-than-average car is one of many vastly more significant risks we assume when we take to the highway.

I certainly don’t wish to exonerate or condemn Firestone and Ford executives, as I have no idea what they knew nor when they knew it. The suggestion, however, that they may have known a lot about the problem early on is what has attracted so much media interest, not the number of deaths themselves. In this regard the story is not different from many others in which human wrongdoing holds much more fascination for people than the relevant numbers.

Bad Doctors, Operators

Consider too the media coverage of last year’s Institute of Medicine report on the inordinate number of deaths due to medical mismanagement. Much of it focused on doctors’ egregious mistakes — amputating the wrong leg, say — and not on the many small changes in the system that could save tens of thousands of lives annually. Again, misbehavior seems to attract more attention than inefficient routines even when the latter kill more people.

  • 1
  • |
  • 2
Join the Discussion
blog comments powered by Disqus
You Might Also Like...