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Effects of television viewing on child developmentARTICLE from the Encyclopdia BritannicaEffects of television viewing on child development, highly contested topic within child development and psychology involving the consequences for children from the content of and the duration of their exposure to television (TV) programming. The effects of television viewing on child development have aroused a range of reactions from researchers, parents, and politicians that has fueled a debate that extends back to the mediums inception in the 1940s.It is difficult to argue that youths are not affected by what is broadcast on television. However, it is equally difficult to pinpoint particular shows or genres of programming as causing specific behaviours in children without considering the innumerable amount of alternate influences that may have an effect on their actions. Some have argued that television clearly has negative effects on youthssuch as violent programming resulting in children who are more fearful, more aggressive, or more insensitive to the suffering of otherswhereas others believe that such effects are, at best, ambiguous. Although it is uncertain which perspective is right or wrong, it is quite certain that the debate continues to galvanize social scientists, parents, and politicians in the United States and elsewhere.Early findingsAs commercial television began to flourish in the United States in the 1940s, televisions effects on the first generation of individuals raised alongside the new medium became a topic of interest. In 1949 the Columbia Broadcasting System (CBS) sponsored a study conducted by Rutgers University that found that television increased family unity and cohesion, did not promote viewer passivity, and did not replace other valued diversions, such as outdoor activities and social interactions. That landmark report was one of the first and most widely disseminated of its kind, and several more would follow in the forthcoming decade. Soon, however, questions were raised about whether television viewing decreased dialogue between children and parents and whether children could be expected to maintain academic progress as their average total viewing time increased to more than 20 hours a week. Eventually, broadcasters capitalized upon those youthful watchers by developing targeted programs such as puppet shows and Saturday morning cartoons. Although those were highly popular, many childrenespecially those from households that provided minimal parental involvement in viewing choiceswere also watching wrestling shows, TV westerns, and mystery-crime dramas, all of which incorporated a significant amount of violence into their story lines. That, in turn, raised even more concerns about the impact of television on American youth.Effects of television violenceIn several studies in the 1960s and 70s, American psychologist Albert Bandura found that children learn from and imitate the behaviour of individuals they observe, specifically when the individual is rewarded for aggressive acts. That finding corroborated the admonitions of those who suggested that children who constantly witnessed their favorite TV “heroes” being praised for beating up or killing the “bad guy” would, in turn, incorporate aggressive acts into their own repertoire of behaviours for use in situations characterized by conflict. Throughout the following decades, psychologists, sociologists, criminologists, and other social scientists have argued a number of different perspectives with respect to whether television violence facilitates or triggers violent behaviours in children. Some believe that watching violence on television likely causes a significant number of children to behave violently. Others have agreed that this may be true but that it is so only with children already susceptible to exhibiting violence. As a result, some have argued for tighter controls, either voluntary or legislative, concerning what should be allowed on the airwaves. Alternately, some have blamed parents instead of the broadcast industry and contended that parents are ultimately to blame for their childrens viewing habits. A general point of agreement (or compromise) among the research community is that television can have effects on childrens behaviour but that it must be considered as one of many determinants that may cause a child to act in a particular manner.Other potential effectsThe debate of whether violence on television begets violence in children may be the most-salient issue, but some social scientists argue that television programming has negative effects on children beyond promoting aggressive behaviour. For example, television shows appear to perpetuate gender and racial stereotypes and offer young viewers a distorted perspective of how the world works and how people behave. Several studies have correlated television with deficits in attention and focus and have revealed negative correlations between test scores and the number of hours of programming watched. In addition, parents have complained about the content of certain shows, contending that even the most “child-friendly” programming may present values (especially those regarding sex, alcohol, tobacco, and illicit drug use) that contradict those they wish to pass on to their offspring.Health care professionals have also weighed in on the television debate. They believe that children who spend more time watching television are going to spend less time engaging in physical activity. That trend, combined with the ubiquity of fast-food advertisements during such programs, may be largely responsible for Americas obesity epidemic. Additionally, psychologists argue that the large amount of time spent watching TV threatens the cohesiveness of the family. Such negative effects may also include inhibiting childrens social development by diminishing the number of conversations between them and their family members.Despite all the negative influences attributed to television, some commentators note that the medium can have a positive effect on youths. For instance, television programs are quite commonly used in school classrooms, and teachers may use educational videos or segments recorded from network broadcasts to accentuate their lessons and provide learning avenues for children with different learning styles. Also, television has exposed people to a wider array of cultures and societies and has made more young people aware of political and social issues, which in turn may increase their influence on their respective nations government.Policy issuesBecause of the television-viewing habits of youths, some legislators have advocated for stricter regulation of what is shown on TV. In the United States in 1996, Congress mandated that V-chips, devices that parents can use to block programming inappropriate for children, be installed in every television set produced after 1999. In 1997 the entertainment industry, pressured by Congress to enact a ratings system to work in conjunction with the V-chip, developed the TV Parental Guidelines, a ratings system based somewhat on the Motion Picture Association of Americas long-standing system of rating movies, where television shows are marked as “Y” (young children), “Y7” (older children), “G” (general audience), “PG” (parental guidance suggested), “14” (parents strongly cautioned), and “MA” (mature audiences). Studies indicate that most parents do not use the V-chip, which may render the effects of such legislation negligible.Although members of the television-broadcasting community have been largely compliant in providing ratings and guidelines for their shows, they generally challenge governmental attempts to restrict their product. In essence, they argue that television is part of the free-enterprise system, and any attempt to control its content violates constitutional principles. They argue that their programming reflects events and actions already taking place in the world and is not their cause. Critics of that position argue that most countries have laws that ensure that television programming is regulated in order to make certain that what is aired does not contradict laws guarding against public indecency and obscenity.John L. Powell IIIMichael C. RobertsTV violence and self-regulationAlthough the FCC is forbidden to regulate the content of television (except for content unprotected by the First Amendment and that falling under the indecency rule), the agency strongly urged networks to adopt a system of self-regulation in the mid-1970s. In 1975 the chairman of the FCC, Richard Wiley, reportedly encouraged the networks to limit violent programming to time slots after 9:00 pm Eastern Standard Time. Arthur Taylor, then president of CBS, became the chief advocate of what became known as “family viewing time” (8:009:00 pm, as far as the networks were concerned), and he enlisted the support of the other networks as well. Many producers, on the other hand, were not eager to offer their support. Among other things, they were concerned that the family viewing time agreement would restrict the times in which stations could air their shows in syndication. All in the Familys producer, Norman Lear, who at the time had several adult-themed shows airing on the networks between 8:00 and 9:00 pm, led the attack on the idea, claiming First Amendment rights and declaring that the networks had broken antitrust regulations by conspiring to bring family viewing time into being. A Los Angeles federal district court disallowed the self-regulatory action in 1976.The issue of television violence reemerged in the early 1970s with the publication of the Surgeon Generals Scientific Advisory Committee on Television and Social Behaviors five-volume report in 1972. The surgeon general told a Senate committee that “the overwhelming consensus and the unanimous Scientific Advisory Committees report indicates that televised violence, indeed, does have an adverse effect on certain members of our society.” The report encouraged remedial action, but the FCC, limited by the First Amendment, took no action until 1996, when it mandated a ratings system designed to inform parents of programs that might be inappropriate for children. Over the next decade, however, several important legal cases addressed the relationship between violence on TV and violent behaviour among television viewers. In Zamora et al. v. Columbia Broadcasting System et al. (1979), the parents of a 15-year-old boy who killed his neighbour sued a television network for “intoxicating” their son with TV violence. In 1981 the complainants in Niemi v. National Broadcasting Company argued that the mechanics of a brutal rape were learned on a made-for-TV movie called Born Innocent (NBC, 1974). Other cases not directly related to violence sought to hold television broadcasters responsible for behaviour learned from their programs. A boy who was partially blinded while performing an experiment demonstrated on The Mickey Mouse Club was the subject of Walt Disney Productions et al. v. Shannon et al. (1981), and DeFilippo v. National Broadcasting Company et al. (1982) brought suit against NBC after a youth hanged himself while imitating a stunt mans demonstration he had seen on The Tonight Show.air pollutionPrimary Contributor: Jerry A. Nathanson ARTICLEfrom theEncyclopdia BritannicaGet involved Share air pollution,release into the atmosphere of various gases, finely divided solids, or finely dispersed liquid aerosols at rates that exceed the natural capacity of the environment to dissipate and dilute or absorb them. These substances may reach concentrations in the air that cause undesirable health, economic, or aesthetic effects.Major air pollutantsCriteria pollutantsClean, dry air consists primarily of nitrogen and oxygen78 percent and 21 percent respectively, by volume. The remaining 1 percent is a mixture of other gases, mostly argon (0.9 percent), along with trace (very small) amounts of carbon dioxide, methane, hydrogen, helium, and more. Water vapour is also a normal, though quite variable, component of the atmosphere, normally ranging from 0.01 to 4 percent by volume; under very humid conditions the moisture content of air may be as high as 5 percent.The gaseous air pollutants of primary concern in urban settings include sulfur dioxide, nitrogen dioxide, and carbon monoxide; these are emitted directly into the air from fossil fuels such as fuel oil, gasoline, and natural gas that are burned in power plants, automobiles, and other combustion sources. Ozone (a key component of smog) is also a gaseous pollutant; it forms in the atmosphere via complex chemical reactions occurring between nitrogen dioxide and various volatile organic compounds (e.g., gasoline vapours).Airborne suspensions of extremely small solid or liquid particles called “particulates” (e.g., soot, dust, smokes, fumes, mists), especially those less than 10 micrometres (m; millionths of a metre) in size, are significant air pollutants because of their very harmful effects on human health. They are emitted by various industrial processes, coal- or oil-burning power plants, residential heating systems, and automobiles. Lead fumes (airborne particulates less than 0.5 m in size) are particularly toxic.The six major air pollutants listed above have been designated by the U.S. Environmental Protection Agency (EPA) as “criteria” pollutantscriteria meaning that the concentrations of these pollutants in the atmosphere are useful as indicators of overall air quality.Except for lead, criteria pollutants are emitted in industrialized countries at very high rates, typically measured in millions of tons per year. All except ozone are discharged directly into the atmosphere from a wide variety of sources. They are regulated primarily by establishing ambient air quality standards, which are maximum acceptable concentrations of each criteria pollutant in the atmosphere, regardless of its origin. The six criteria pollutants are described in turn below.Fine particulates Very small fragments of solid materials or liquid droplets suspended in air are called particulates. Except for airborne lead, which is treated as a separate category (see below), they are characterized on the basis of size and phase (i.e., solid or liquid) rather than by chemical composition. For example, solid particulates between roughly 1 and 100 m in diameter are called dust particles, whereas airborne solids less than 1 m in diameter are called fumes.The particulates of most concern with regard to their effects on human health are solids less than 10 m in diameter, because they can be inhaled deep into the lungs and become trapped in the lower respiratory system. Certain particulates, such as asbestos fibres, are known carcinogens (cancer-causing agents), and many carbonaceous particulatese.g., sootare suspected of being carcinogenic. Major sources of particulate emissions include fossil-fuel power plants, manufacturing processes, fossil-fuel residential heating systems, and gasoline-powered vehicles.Carbon monoxide Carbon monoxide is an odourless, invisible gas formed as a result of incomplete combustion. It is the most abundant of the criteria pollutants. Gasoline-powered highway vehicles are the primary source, although residential heating systems and certain industrial processes also emit significant amounts of this gas. Power plants emit relatively little carbon monoxide because they are carefully designed and operated to maximize combustion efficiency. Exposure to carbon monoxide can be acutely harmful since it readily displaces oxygen in the bloodstream, leading to asphyxiation at high enough concentrations and exposure times.Sulfur dioxide A colourless gas with a sharp, choking odour, sulfur dioxide is formed during the combustion of coal or oil that contains sulfur as an impurity. Most sulfur dioxide emissions come from power-generating plants; very little comes from mobile sources. This pungent gas can cause eye and throat irritation and harm lung tissue when inhaled. It also reacts with oxygen and water vapour in the air, forming a mist of sulfuric acid that reaches the ground as a component of acid rain. Acid rain is believed to have harmed or destroyed fish and plant life in many thousands of lakes and streams in parts of Europe, the northeastern United States, southeastern Canada, and parts of China. It also causes corrosion of metals and deterioration of the exposed surfaces of buildings and public monuments.Nitrogen dioxide Of the several forms of nitrogen oxides, nitrogen dioxidea pungent, irritating gasis of most concern. It is known to cause pulmonary edema, an accumulation of excessive fluid in the lungs. Nitrogen dioxide also reacts in the atmosphere to form nitric acid, contributing to the problem of acid rain. In addition, nitrogen dioxide plays a role in the formation of photochemical smog, a reddish brown haze that often is seen in many urban areas and that is created by sunlight-promoted reactions in the lower atmosphere.Nitrogen oxides are formed when combustion temperatures are high enough to cause molecular nitrogen in the air to react with oxygen. Stationary sources such as coal-burning power plants are major contributors of this pollutant, although gasoline engines and other mobile sources are also significant.OzoneA key component of photochemical smog, ozone is formed by a complex reaction between nitrogen dioxide and hydrocarbons in the presence of sunlight. It is considered to be a criteria pollutant in the tropospherethe lowermost layer of the atmospherebut not in the upper atmosphere, where it occurs naturally and serves to block harmful ultraviolet rays from the Sun. Because nitrogen dioxide and hydrocarbons are emitted in significant quantities by motor vehicles, photochemical smog is