It is common to worry that depictions of bad things have a negative impact on human behaviour. Violent movies and video games are turning young children into killers! Smutty advertising is normalising promiscuity; violent porn turns men into rapists and misogynists! Child porn will convert normal men into sex offenders! Maybe these materials do have that effect. People sometimes emulate what they see, so they’re hardly crazy ideas. However, whenever you hear a claim like this, it’s worth keeping in mind that the exact opposite effect is also a possibility.
Perhaps violent video games keep violent people on the couch where they can’t hurt anyone. Perhaps pornography sexually satisfies men who would otherwise be tempted to sexually assault someone. Perhaps having child porn on hand reduces the motivation of more moderate paedophiles to actually assault children in real life.
Working out whether the ‘example or complement effect’ or the ‘substitution effect’ dominates is an empirical question that is impossible to resolve from the armchair.
For preferences that are easily satisfied, there is good reason to think the substitution effect can be big and the ‘example effect’ small:
“Berl Kutchinsky, studied Denmark, Sweden, West Germany, and the United States in the 1970s and 1980s. He showed that for the years from approximately 1964 to 1984, as the amount of pornography increasingly became available, the rate of rapes in these countries either decreased or remained relatively level. Later research has shown parallel findings in every other country examined, including Japan, Croatia, China, Poland, Finland, and the Czech Republic. In the United States there has been a consistent decline in rape over the last 2 decades, and in those countries that allowed for the possession of child pornography, child sex abuse has declined. … Richard Green too has reported that both rapists and child molesters use less pornography than a control group of “normal” males. … Studies of men who had seen X-rated movies found that they were significantly more tolerant and accepting of women than those men who didn’t see those movies, and studies by other investigators—female as well as male—essentially found similarly that there was no detectable relationship between the amount of exposure to pornography and any measure of misogynist attitudes. No researcher or critic has found the opposite, that exposure to pornography—by any definition—has had a cause-and-effect relationship towards ill feelings or actions against women. No correlation has even been found between exposure to porn and calloused attitudes toward women.”
Steven Lansberg finds similar results from the roll-out of porn on the internet, and finds violence goes down in response to violent films, at least in the short run:
What happens when a particularly violent movie is released? Answer: Violent crime rates fall. Instantly. Here again, we have a lot of natural experiments: The number of violent movie releases changes a lot from week to week. One weekend, 12 million people watch Hannibal, and another weekend, 12 million watch Wallace & Gromit: The Curse of the Were-Rabbit.
University of California professors Gordon Dahl and Stefano DellaVigna compared what happens on those weekends. The bottom line: More violence on the screen means less violence in the streets. Probably that’s because violent criminals prefer violent movies, and as long as they’re at the movies, they’re not out causing mischief. They’d rather seeHannibal than rob you, but they’d rather rob you than sit through Wallace & Gromit.
Maybe there is an example effect from video games though:
The current issue of the journal Psychological Bulletin addresses this issue with no fewer than four articles, beginning with a new meta-analytic review credited to eight researchers from the U.S. and Japan. They found unambiguous evidence that such games are a “causal risk factor” for increased aggression and decreased empathy among the people who play them.
Their analysis “yielded strong evidence that playing violent video games is a significant risk factor for both short-term and long-term increases in physically aggressive behavior,” writes Iowa State University psychologist Craig Anderson, the paper’s lead author. This connection was seen “regardless of research design or conservativeness of analysis,” and was true for both men and women, older and younger players, and those in Eastern and Western nations.
Though not a strong one, protests Andy McKenzie:
The most recent meta analysis (abstract here) finds that the longitudinal causal effect of playing violent video games after adjusting for initial aggression and sex has an r value of 0.152, for a percentage variance explained of only 2.31%. The authors of this study argue that small effect sizes can have high practical significance if they accumulate over time or if high proportions of the population are exposed. That may be; it’s hard to say. But we do know this: 2.31% variance explained is not a particularly large effect size.
These are complex questions that require plenty of data to resolve. When a campaigner tries to sell you a simple example or substitute story, be skeptical.
Tagged: economics, psychology
