Spending too much time in front of the television may be unhealthy for both young adults and people with certain personality traits. A pair of studies details the risks.
The first study, published online in the International Journal of Injury Control and Safety Promotion, suggests people with hostile personality traits who watch a lot of television may be at a greater risk for injury—possibly because they are more susceptible to the influence of television on violence and risk-taking behaviors, researchers say.
A reduction in television viewing and a content rating systems that is geared not just to age, but also to personality traits, could help.
“Television viewing is very pervasive, with televisions in almost 99 percent of American households,” says Anthony Fabio, assistant professor of epidemiology at the University of Pittsburgh.
“And injuries cause more than half the deaths among people ages 1 through 44. This means that even modest reductions in television viewing, particularly among people predisposed to hostility, could have major positive outcomes for public health.”
For the study, researchers analyzed data from 4,196 adults recruited from Birmingham, Ala., Chicago, Minneapolis, and Oakland, Calif., who participated in the Coronary Artery Risk Development in Young Adults (CARDIA) Study. For 15 years starting in 1990, participants periodically reported their television viewing habits and completed in-depth questionnaires to assess their personality traits. Researchers also recorded all injuries requiring hospitalization.
As the amount of television viewing increased, so did the risk of injuries in the next five years. Notably, this relationship risk was greater for those in the “high hostility” group, which was determined by a scientific questionnaire. For example, for high-hostile individuals, watching more TV at year five was associated with 40 percent higher odds of injury at year 10. Additionally, watching more TV at year 15 was associated with a doubling in the odds of injury at year 20. The association did not occur in individuals with less hostile personalities.
Television and injuries
There are several research-backed explanations for why more television watching can lead to such a pronounced increase in injuries among people predisposed to hostility:
- People often imitate new behaviors that they witness, leading them to participate in more high-risk behaviors if they watch more television.
- Media violence and high-risk activities increase psychological arousal, intensifying subsequent behavior, such as aggressive risk-taking or impulsivity.
- Images on television may desensitize people to violence or risk-taking.
“Prevention programs should target both the content of television programs and the amount of time people spend watching television,” Fabio says. “In addition, future studies should be conducted to determine the impact of modifying television viewing habits, particularly in relation to the personality traits of viewers.”
The second study, published in the journal SAGE Open, suggests the more hours young adults spend watching television each day, the greater the likelihood that they’ll have a higher body mass index and bigger waist circumference.
The association did not hold in later years, indicating that young adulthood is an important time to intervene and promote less television viewing, researchers say.
“We were quite surprised to find that television viewing was associated with subsequent obesity for young adults, but not for the middle-aged,” Fabio says. “This suggests that middle-aged adults may differ from young adults in how they respond to the influence of TV viewing.”
TV and BMI
For the study, researchers analyzed data from 3,269 adults recruited from the CARDIA study. For 15 years starting in 1990, participants reported their television viewing habits and had their waist circumference measured and their body mass index (a measure of weight and height that can indicate obesity) calculated every five years.
The more time participants spent watching television when they were approximately 30 years old, the more likely they were to be obese five years later, compared to their peers who spent less time in front of the television. The team did not have data on younger ages.
Results of the analysis show that 23 percent of the men and 20.6 percent of the women participating in the study watched four or more hours of television daily. Within that group of heavy TV watchers, 35.9 percent were black and 8.6 percent were white; 40.8 percent had a high school education or less and 17.4 percent had an education beyond high school. A lower family income and higher rates of smoking and drinking were also associated with more time spent watching television.
“Television viewing and obesity are both highly prevalent in many populations around the world,” Fabio says. “This means that even small reductions in television viewing could lead to vast public health improvements. Reducing sedentary time should be a healthy lifestyle guideline heavily promoted to the public. Our study indicates that the biggest bang for the buck would be in targeting young adults for interventions to reduce television viewing. Healthy lifestyle behaviors should start at early ages.”
Source: University of Pittsburgh