In the social sciences, unintended consequences (sometimes unanticipated consequences or unforeseen consequences) are outcomes of a purposeful action that are not intended or foreseen. The term was popularised in the twentieth century by American sociologist Robert K. Merton.
Unintended consequences can be grouped into three types:
The idea of unintended consequences dates back at least to John Locke who discussed the unintended consequences of interest rate regulation in his letter to Sir John Somers, Member of Parliament.
The idea was also discussed by Adam Smith, the Scottish Enlightenment, and consequentialism (judging by results).
Sociologist Robert K. Merton popularised this concept in the twentieth century.
In "The Unanticipated Consequences of Purposive Social Action" (1936), Merton tried to apply a systematic analysis to the problem of unintended consequences of deliberate acts intended to cause social change. He emphasized that his term purposive action, "[was exclusively] concerned with 'conduct' as distinct from 'behavior.' That is, with action that involves motives and consequently a choice between various alternatives".Merton's usage included deviations from what Max Weber defined as rational social action: instrumentally rational and value rational. Merton also stated that "no blanket statement categorically affirming or denying the practical feasibility of all social planning is warranted."
More recently, the law of unintended consequences has come to be used as an adage or idiomatic warning that an intervention in a complex system tends to create unanticipated and often undesirable outcomes.
Akin to Murphy's law, it is commonly used as a wry or humorous warning against the hubristic belief that humans can fully control the world around them.
Possible causes of unintended consequences include the world's inherent complexity (parts of a system responding to changes in the environment), perverse incentives, human stupidity, self-deception, failure to account for human nature, or other cognitive or emotional biases. As a sub-component of complexity (in the scientific sense), the chaotic nature of the universe—and especially its quality of having small, apparently insignificant changes with far-reaching effects (e.g., the butterfly effect)—applies.
In 1936, Robert K. Merton listed five possible causes of unanticipated consequences:
In addition to Merton's causes, psychologist Stuart Vyse has noted that groupthink, described by Irving Janis, has been blamed for some decisions that result in unintended consequences.
The creation of "no-man's lands" during the Cold War, in places such as the border between Eastern and Western Europe, and the Korean Demilitarized Zone, has led to large natural habitats.
The sinking of ships in shallow waters during wartime has created many artificial coral reefs, which can be scientifically valuable and have become an attraction for recreational divers. Retired ships have been purposely sunk in recent years, in an effort to replace coral reefs lost to global warming and other factors.
In medicine, most drugs have unintended consequences ('side effects') associated with their use. However, some are beneficial. For instance, aspirin, a pain reliever, is also an anticoagulant that can help prevent heart attacks and reduce the severity and damage from thrombotic strokes.The existence of beneficial side effects also leads to off-label use—prescription or use of a drug for an unlicensed purpose. Famously, the drug Viagra was developed to lower blood pressure, with its use for treating erectile dysfunction being discovered as a side effect in clinical trials.
The implementation of a profanity filter by AOL in 1996 had the unintended consequence of blocking residents of Scunthorpe, North Lincolnshire, England from creating accounts due to a false positive.The accidental censorship of innocent language, known as the Scunthorpe problem, has been repeated and widely documented.
In 1990, the Australian state of Victoria made safety helmets mandatory for all bicycle riders. While there was a reduction in the number of head injuries, there was also an unintended reduction in the number of juvenile cyclists—fewer cyclists obviously leads to fewer injuries, assuming all else being equal. The risk of death and serious injury per cyclist seems to have increased, possibly due to risk compensation.Research by Vulcan, et al. found that the reduction in juvenile cyclists was because the youths considered wearing a bicycle helmet unfashionable. A health-benefit model developed at Macquarie University in Sydney suggests that, while helmet use reduces "the risk of head or brain injury by approximately two-thirds or more", the decrease in exercise caused by reduced cycling as a result of helmet laws is counterproductive in terms of net health.
Prohibition in the 1920s United States, originally enacted to suppress the alcohol trade, drove many small-time alcohol suppliers out of business and consolidated the hold of large-scale organized crime over the illegal alcohol industry. Since alcohol was still popular, criminal organisations producing alcohol were well-funded and hence also increased their other activities. Similarly, the War on Drugs, intended to suppress the illegal drug trade, instead increased the power and profitability of drug cartels who became the primary source of the products.
In CIA jargon, "blowback" describes the unintended, undesirable consequences of covert operations, such as the funding of the Afghan Mujahideen and the destabilization of Afghanistan contributing to the rise of the Taliban and Al-Qaeda.
The introduction of exotic animals and plants for food, for decorative purposes, or to control unwanted species often leads to more harm than good done by the introduced species.
The protection of the steel industry in the United States reduced production of steel in the United States, increased costs to users, and increased unemployment in associated industries.
In 2003, Barbra Streisand unsuccessfully sued Kenneth Adelman and Pictopia.com for posting a photograph of her home online.Before the lawsuit had been filed, only 6 people had downloaded the file, two of them Streisand's attorneys. The lawsuit drew attention to the image, resulting in 420,000 people visiting the site. The Streisand Effect was named after this incident, describing when an attempt to censor or remove a certain piece of information instead draws attention to the material being suppressed, resulting in the material instead becoming widely known, reported on, and distributed.
Passenger-side airbags in motorcars were intended as a safety feature, but led to an increase in child fatalities in the mid-1990s because small children were being hit by airbags that deployed automatically during collisions. The supposed solution to this problem, moving the child seat to the back of the vehicle, led to an increase in the number of children forgotten in unattended vehicles, some of whom died under extreme temperature conditions.
Risk compensation, or the Peltzman effect, occurs after implementation of safety measures intended to reduce injury or death (e.g. bike helmets, seatbelts, etc.). People may feel safer than they really are and take additional risks which they would not have taken without the safety measures in place. This may result in no change, or even an increase, in morbidity or mortality, rather than a decrease as intended.
According to an anecdote, the British government, concerned about the number of venomous cobra snakes in Delhi, offered a bounty for every dead cobra. This was a successful strategy as large numbers of snakes were killed for the reward. Eventually, enterprising people began breeding cobras for the income. When the government became aware of this, they scrapped the reward program, causing the cobra breeders to set the now-worthless snakes free. As a result, the wild cobra population further increased. The apparent solution for the problem made the situation even worse, becoming known as the Cobra effect.
Theobald Mathew's temperance campaign in 19th-century Ireland resulted in thousands of people vowing never to drink alcohol again. This led to the consumption of diethyl ether, a much more dangerous intoxicant — due to its high flammability — by those seeking to become intoxicated without breaking the letter of their pledge.
It was thought that adding south-facing conservatories to British houses would reduce energy consumption by providing extra insulation and warmth from the sun. However, people tended to use the conservatories as living areas, installing heating and ultimately increasing overall energy consumption.
A reward for lost nets found along the Normandy coast was offered by the French government between 1980 and 1981. This resulted in people vandalizing nets to collect the reward.
Beginning in the 1940s and continuing into the 1960s, the Canadian federal government gave the Catholic Church in Quebec $2.25 per day per psychiatric patient for their cost of care, but only $0.75 a day per orphan. The perverse result is that the orphan children were diagnosed as mentally ill so the church could receive the larger amount of money. This psychiatric misdiagnosis affected up to 20,000 people, and the children are known as the Duplessis Orphans.
There have been attempts to curb the consumption of sugary beverages by imposing a tax on them. However, a study found that the reduced consumption was only temporary. Also, there was an increase in the consumption of beer among households.
The New Jersey Childproof Handgun Law, which was intended to protect children from accidental discharge of firearms by forcing all future firearms sold in New Jersey to contain "smart" safety features, has delayed, if not stopped entirely, the introduction of such firearms to New Jersey markets. The wording of the law caused significant public backlash,fuelled by gun rights lobbyists, and several shop owners offering such guns received death threats and stopped stocking them In 2014, 12 years after the law was passed, it was suggested the law be repealed if gun rights lobbyists agree not to resist the introduction of "smart" firearms.
Drug prohibition can lead drug traffickers to prefer stronger, more dangerous substances, that can be more easily smuggled and distributed than other, less concentrated substances.
Televised drug prevention advertisements may lead to increased drug use.
Increasing usage of search engines, also including recent image search features, has contributed in the ease of which media is consumed. Some abnormalities in usage may have shifted preferences for pornographic film actors, as the producers began using common search queries or tags to label the actors in new roles.
The passage of the Stop Enabling Sex Traffickers Act has led to a reported increase in risky behaviors by sex workers as a result of quashing their ability to seek and screen clients online, forcing them back onto the streets or into the dark web. The ads posted were previously an avenue for advocates to reach out to those wanting to escape the trade.
The legalization of commercial Cannabis growth in California, meant in part to decrease the risk of violence to users and growers, reportedly led to an increase in murders in Humboldt County, which is responsible for the majority of cannabis produced in the US.
According to Lynn White, the invention of the horse stirrup enabled new patterns of warfare that eventually led to the development of feudalism (see Great Stirrup Controversy).
Most modern technologies have negative consequences that are both unavoidable and unpredictable. For example, almost all environmental problems, from chemical pollution to global warming, are the unexpected consequences of the application of modern technologies. Traffic congestion, deaths and injuries from car accidents, air pollution, and global warming are unintended consequences of the invention and large scale adoption of the automobile. Hospital infections are the unexpected side-effect of antibiotic resistance, and even human overpopulation is the side effect of various technological (i.e., agricultural and industrial) revolutions.
Because of the complexity of ecosystems, deliberate changes to an ecosystem or other environmental interventions will often have (usually negative) unintended consequences. Sometimes, these effects cause permanent irreversible changes. Examples include:
The "Streisand effect" is what happens when someone tries to suppress something and the opposite occurs. The act of suppressing it raises the profile, making it much more well known than it ever would have been
A perverse incentive is an incentive that has an unintended and undesirable result that is contrary to the intentions of its designers. Perverse incentives are a type of negative unintended consequence. A classic example of a perverse incentive occurred when the British government offered a bounty for dead cobras with the intent of decreasing the wild cobra population. However, enterprising people began to breed cobras for the income. When the government became aware of this, the reward program was scrapped, causing the cobra breeders to set the now-worthless snakes free. As a result, the wild cobra population further increased. The term cobra effect was coined to describe a situation where an attempted solution to a problem actually makes the problem worse.
In medicine, a side effect is an effect, whether therapeutic or adverse, that is secondary to the one intended; although the term is predominantly employed to describe adverse effects, it can also apply to beneficial, but unintended, consequences of the use of a drug. Developing drugs is a complicated process, because no two people are exactly the same, so even drugs that have virtually no side effects, might be difficult for some people. Also, it is difficult to make a drug that targets one part of the body but that does not affect other parts, the fact that increases the risk of side effects in the untargeted parts.
Robert King Merton was an American sociologist who is considered a founding father of modern sociology, and a major contributor to the subfield of criminology. He spent most of his career teaching at Columbia University, where he attained the rank of University Professor. In 1994 he was awarded the National Medal of Science for his contributions to the field and for having founded the sociology of science.
Technological utopianism is any ideology based on the premise that advances in science and technology could and should bring about a utopia, or at least help to fulfill one or another utopian ideal.
A bicycle helmet is designed to attenuate impacts to the head of a cyclist in falls while minimizing side effects such as interference with peripheral vision. There is ongoing scientific research into the degree of protection offered by bicycle helmets in the event of an accident, and the effects of helmet wearing on cyclist and motor vehicle driver behaviour.
Risk compensation is a theory which suggests that people typically adjust their behavior in response to the perceived level of risk, becoming more careful where they sense greater risk and less careful if they feel more protected. Although usually small in comparison to the fundamental benefits of safety interventions, it may result in a lower net benefit than expected.
Techno-progressivism or tech-progressivism is a stance of active support for the convergence of technological change and social change. Techno-progressives argue that technological developments can be profoundly empowering and emancipatory when they are regulated by legitimate democratic and accountable authorities to ensure that their costs, risks and benefits are all fairly shared by the actual stakeholders to those developments.
According to Robin A. Williams and David Edge (1996), "Central to social shaping of technology (SST) is the concept that there are choices inherent in both the design of individual artifacts and systems, and in the direction or trajectory of innovation programs."
A cascade effect is an inevitable and sometimes unforeseen chain of events due to an act affecting a system. If there is a possibility that the cascade effect will have a negative impact on the system, it is possible to analyze the effects with a consequence/impact analysis. Cascade effects are commonly visualised in tree structures, also called event trees.
Middle-range theory, developed by Robert K. Merton, is an approach to sociological theorizing aimed at integrating theory and empirical research. It is currently the de facto dominant approach to sociological theory construction, especially in the United States.
Manifest and latent functions are social scientific concepts created by anthropologist, Bronislaw Malinowski in 1922 while studying the Trobiand Islanders in the Western Pacific. It was later modified for sociology by Robert K. Merton. Merton appeared interested in sharpening the conceptual tools to be employed in a functional analysis.
Patient safety is a discipline that emphasizes safety in health care through the prevention, reduction, reporting, and analysis of medical error that often leads to adverse effects. The frequency and magnitude of avoidable adverse events experienced by patients was not well known until the 1990s, when multiple countries reported staggering numbers of patients harmed and killed by medical errors. Recognizing that healthcare errors impact 1 in every 10 patients around the world, the World Health Organization calls patient safety an endemic concern. Indeed, patient safety has emerged as a distinct healthcare discipline supported by an immature yet developing scientific framework. There is a significant transdisciplinary body of theoretical and research literature that informs the science of patient safety.
Party and play is the consumption of drugs to facilitate or enhance sexual activity. Sociologically, it refers to a subculture of recreational drug users who engage in high-risk sexual activities under the influence of drugs within sub-groups. This can include little use of condoms during sessions with multiple sexual partners that may continue for days.
The Free Speech Flag is a symbol of personal liberty used to promote freedom of speech. Designed by artist John Marcotte, the flag and its colors correspond to a cryptographic key which enabled users to copy HD DVDs and Blu-ray Discs. It was created on May 1, 2007, during the AACS encryption key controversy.
Prescription cascade is the process whereby the side effects of drugs are misdiagnosed as symptoms of another problem, resulting in further prescriptions and further side effects and unanticipated drug interactions, which itself may lead recursively to further misdiagnoses and further symptoms. This is a pharmacological example of a feedback loop. Such cascades can be reversed through deprescribing.
The Streisand effect is a social phenomenon that occurs when an attempt to hide, remove, or censor information has the unintended consequence of further publicizing that information, often via the Internet. It is named after American entertainer Barbra Streisand, whose attempt to suppress the California Coastal Records Project's photograph of her residence in Malibu, California, taken to document California coastal erosion, inadvertently drew further attention to it in 2003.
The cobra effect occurs when an attempted solution to a problem makes the problem worse, as a type of unintended consequence. The term is used to illustrate the causes of incorrect stimulation in economy and politics.
The hydra effect or hydra paradox owes its name to the Greek legend of the Lernaean Hydra which grew two heads for each one cut off, and is used figuratively for counter-intuitive effects of actions to reduce a problem which result in stimulating its multiplication. Most notably scientists have proposed that ecological systems can exhibit a hydra effect when "a higher death rate in a particular species ultimately increases the size of its population". The hypothesis is suggested to have implications for the eradication of pests, and resource management. There are also said to be indications that reducing the death rate can shrink a population.
The Bartley-Fox Law is a Massachusetts law that sets a one-year mandatory minimum sentence for anyone found to be illegally carrying a firearm. It was passed by the Massachusetts General Court in 1974 and took effect in April 1975. Studies on its effectiveness have been mixed, and its strict provisions have been subject to criticism.
A disulfiram-like drug is a drug that causes an adverse reaction to alcohol leading to nausea, vomiting, flushing, dizziness, throbbing headache, chest and abdominal discomfort, and general hangover-like symptoms among others. These effects are caused by accumulation of acetaldehyde, a major but toxic metabolite of alcohol formed by the enzyme alcohol dehydrogenase. The reaction has been variously termed a disulfiram-like reaction, alcohol intolerance, and acetaldehyde syndrome.