This summer, friends who live a few kilometers from us in rural Montana in the western US had to interrupt their dinner when a black bear suddenly came out of the trees. They went indoors to watch as it came up to the picnic table, licked the dishes clean, and then drank two cans of beer.
Over the following days, the bear turned over the garbage cans of two neighbors and terrorized children and pets. Forest Service rangers set up a cage and put some bacon inside, soon catching and transporting the bear 30km into the wilderness. The bear was tagged before it was released, to show that it had been causing trouble. "Unfortunately," said the ranger, "that bear may be back here even before our truck returns. Once they develop a taste for bacon and beer, you can't keep them away."
If a tagged bear is caught two or more times causing disruption, the rangers have orders to shoot it.
It is easy to feel sorry for an animal that discovers tasty food and can't resist getting more the easy way. The bear has no idea that its days are numbered unless it remains in the forest and hunts in the traditional way for its meals. But that bear was following the wisdom natural selection had programmed in its genes: food that is high in proteins and sugars is good for you, and the less energy you expend getting it, the better.
That much the bear knows well. It had no chance to learn -- and probably never will -- that picnic tables and garbage cans are defended by forest rangers with orders to kill. How much luckier we humans are, knowing what is good and bad for us. We cannot be trapped so easily by things that taste good but will cause our downfall.
But, in reality, most of us are no different from that bear. Most people are aware that high-fat diets, too much alcohol, smoking, promiscuous sex, and recreational drugs, while pleasant, can ruin one's health. Yet we can't resist the lure of the garbage can and its delights. But at least we have had clear warnings about the dangers of such habits, so people who want to use such knowledge can avoid being trapped.
There are other potentially harmful pleasures in the environment that are less known, but not less destructive than those that are. One of the most seductive of these pleasures -- and thus one of the most dangerous -- is television.
Television is attractive to the architecture of the human nervous system: our brains are built to absorb information and follow rapid changes in the sensory field. TV provides these in easily digestible, sumptuously prepared morsels.
Constant change and the appearance of excitement absorb viewers' attention. The Sistine Chapel cannot compare with it ? most children will become bored after ten minutes by the frescoes of Michelangelo, but will watch a detergent commercial with riveted interest.
All of this applies just to the way the medium works, without taking content into consideration. The content in turn reinforces the seductive qualities of the medium by offering generous helpings of sex, violence, easy comfort and other material that we are genetically prepared to respond to, but that in large doses detract from the ability to lead productive and serene lives.
Indeed, by now the evidence that television watching is a dangerous habit has grown to such proportions that it is a wonder that stronger warnings and effective prevention have not been adopted. Among the many findings is that watching too much television induces passivity, both at the level of neural functioning and of behavior and that it interferes with learning and reduces political and civic participation. It also encourages aggressive behavior in children and produces negative moods such as sadness and loneliness. Nor is there any evidence of benefits to counterbalance these negative effects.