What is the Law of Unintended Consequences?

The law of unintended consequences is the outgrowth of many theories, but was probably best defined by sociologist Robert K. Merton in 1936. Merton wrote an article, The Unanticipated Consequences of Purposive Social Action, which covers five different ways that actions, particularly those taken on a large scale as by governments, may have unexpected consequences. These “reactions,” may be positive, negative or merely neutral, but they veer off from the intent of the initial action. Merton also described five reasons why a “law” or change might fall under the heading of the law of unintended consequences.

The two top reasons why the law of unintended consequences works, according to Merton, is that the framers of a social change are either ignorant of possible far reaching effects of the law or make errors when they develop a change that don’t have the effects they desired. Other reasons why we sometimes see changes occur after any type of event, new scientific development, or treaty is passed may have to do with “self interest,” so much so that a person who desperately wants to see a change doesn’t evaluate the ultimate effects of that change.

A person’s value system may also fail to make them look past their system when taking an action of any kind to evaluate how the law of unintended consequences might work. The fifth cause of the law of unintended consequences is the self-defeating prophecy. In this case, Merton was specifically referring to how society might falsely predict some potential threat to society and to avoid it, might change the society in some important or drastic way.

Any action, from smallest to largest, can have unforeseen results. In a way this is to be expected because even in the smallest systems, like an individual family, individuals are intensely complex beings. When you look at a society as a whole, the mechanisms of it are so convoluted and extraordinarily challenging, that you can expect almost anything that would affect that society to have unintended results.

You could look at how the law of unintended consequences occurs in a family system. For instance, you might decide to sit down with the kids to watch a family movie. The intent may be partly self-interested, since you want to see the movie, and if you’ve never seen it before you may be ignorant of the possibility of consequences occurring from watching the film. Say the five-year old in the family gets badly scared by something that you would view as innocent.

Though the goal may have been to watch the film and have some family time, an unforeseen result rears its head, and you then have a kid who interrupts your sleep for the next year by having nightmares. Sometimes you can’t guess at what an unintended consequence might be. A child might alternately be so impressed by the movie that he or she grows up to be an actor, screenwriter, or a director. These aren’t the goals of family movie night; they’re unanticipated consequences. But the example suggests that even the smallest action can have either negative repercussions or life-altering affects you probably would not have considered.
More frequently, people evaluate how the law of unintended consequences operates on a much larger scale. For example, welfare programs, designed to aid families in economic distress led to the unintended consequence of some folks deliberately staying on welfare and “abusing the system.” This led to welfare reform, especially as enacted by the Clinton era of the 1990s, when people were given a limited time to pull their lives back together.

An unintended consequence of welfare reform was the bind it placed many single mothers in. Since they had to return to work, and they still might lack training to take on high paying work, they had to struggle to find childcare that would be inexpensive enough. Some women who participated in the US welfare to work program found themselves in even greater poverty once they began to work, and the need for inexpensive childcare placed an undue burden on the childcare system, and occasionally placed children in childcare programs that were not well run.
Just about every law, every invention, every treaty, and every large-scale action has unintended consequences, which may alter society as a whole. The advent of antibiotics ushered in cures for illnesses that had previously proved death sentences, but an unintended consequence was the development of superbugs that resist antibiotic treatment. It may be impossible to fully anticipate how any change to a society may ultimately affect it, in many ways, until those effects are already occurring. It’s a law often observed best in hindsight.