One of the mantras often expressed by advocates concerned about media violence is that violent media content may desensitize viewers to real-life violence. This notion of desensitization seems to have intuitive appeal for the pearl-clutching set in direct proportion to its nebulousness as a construct. So what do we mean by desensitization? And does this mean that media makes us more violent ourselves or more indifferent to the suffering of others?
Desensitization, in general, refers to decreased emotional response to aversive stimuli. So you may remember the first time you got behind the wheel of a car, you might have felt nervous, anxious, even terrorized you might smoosh some little old lady trying to cross the road. But after repeated practice, you become an old hat at driving, often finding it boring. Granted you may still be terrible as a driver, but now that only horrifies other people. That's basically desensitization. It's a normal and even adaptive process. Indeed, we use it in treatment for anxiety disorders to decrease fear responses to the objects of phobias.
Media related discussions of desensitization imply that it is always a bad thing, but this is clearly not the case. For instance, emergency responders typically experience less emotional reaction to distressing scenes than the rest of us...and hence are "desensitized" but it's this process that allows them to do their jobs. And few people would argue that emergency responders are uncaring or non-empathic, given they've dedicated their lives to helping others in need.
So the problem with the concept of media violence inducing desensitization is right in the definition. Unlike real-life violence, many people don't find media violence to be aversive. There appears to be a clear distinction in the ways our brains treat and respond to fictional violence and real-life violence in regards to our emotional reaction, as my student Raul Ramos observed in a recent experiment. In that experiment participants felt much more empathy toward victims of real-life violence than victims of fictional movie violence. And it didn't matter whether they'd seen a violent or non-violent television show prior to this.
So if media violence isn't aversive (after all, if it were no one would watch it and we wouldn't be having this debate), what we're talking about isn't really desensitization. But perhaps more critically, the very idea of media desensitization transferring to real-life violence rests on the assumption that our brains do not distinguish between real-life violence and fantasy violence. For instance, the authors of one recent paper asked, explicitly "What psychological theory would explain how observing violence in the home, school, community, or culture would increase the risk of violence but observing it in the mass media or in video games would not increase the risk?" There are, in fact, theories that explain exactly this, but the authors of this question appear to directly equate real-life violence with fictional violence. Some scholars have apparently even tried to imply that fictional media has more effect than abusive parenting or broken homes. One article suggests "Media violence effects on aggression are larger than many other aggression risk factors such as low IQ and child abuse." The technical word for claims such as this is: poppycock. To most people, such insinuations are, of course, patently absurd.
The problem is that many media effects theories assume people are idiots. Ok, some people are idiots, but I mean *really* idiots, in that for brains to work the way some scholars seem to suggest really makes no sense at all. Very few of us are building shelters to survive an alien invasion or using the wands we buy at Universal to try to cast magic spells, so clearly our brains distinguish between reality and fantasy, a process that research now suggests begins very early in childhood and typically is completed by the latter elementary school years.
Evidence for the belief that media influences the brain in ways to promote violence is lacking. Indeed, in 2011, the Supreme Court of the United States brushed aside this notion after reviewing the evidence. Some scholars have attempted to argue for desensitization using brain studies. For example, some studies have used what are called P300 amplitudes in EEG assessments. P300 studies are mainly related to boredom or disengagement, so it's not surprising that showing people the same images (violent or not) over and over would make people less emotionally aroused. Attempts to link these kinds of brain findings to "desensitization" are speculative at best, particularly since some of the outcome measures used to do so have since been revealed to be invalid. Other attempts using fMRIs similarly have been dubious, using tiny samples, "voodoo" statistics and with little evidence that any observed differences have anything to do with increased aggressiveness or decreased empathy. Some studies appear to have been funded by what look like anti-media advocacy groups, a clear conflict of interest. Most of these studies are like Rorschach cards for the scientists conducting them...telling us more about what the scholars hoped to see, not what's really going on in real-life. And, of course, not all such studies find evidence for even these nebulous effects.
Transfer of Learning
Part of the issue for desensitization effects is a concept called transfer of learning. Transfer of learning occurs when learning in one context is applied to another similar context. Such transfer becomes less likely the further two contexts become from each other. When one hopes to transfer learning across contexts that are dissimilar this is called far transfer of learning. Such transfers are unlikely, for the most part. So, being good at the game Operation does not make you a good surgeon. Few of us would seriously consider getting on an airplane if the pilot's training consisted solely of Microsoft's Flight Simulator. But media violence theories of desensitization implicitly require far transfer of learning. We'd need to transfer that learning from the couch with our glass of cola and chips, surrounded by friends and family, and apply that to wholly different contexts such as being cut off on the freeway, or someone staring at our romantic partner oddly while at a club. For this to work, fictional media would have to work on a level greater than educational programs specifically designed to promote transfer of learning. This is why some scholars are explicitly skeptical of such theories. Further evidence continues to mount that such far transfer of learning does not, in fact, occur. Media violence can desensitize you to other media violence, but not much else.
Ultimately the concept of desensitization relies on the weaknesses of media psychology theories that emerged out of the 60s and 70s. Namely, that humans are non-agentic, predictable, imitation machines that do not distinguish (whether as children or adults) between fiction/fantasy and reality. Increasingly, this is an unsatisfying model of the human condition. For media psychology to survive the challenges facing it at present, it will need to begin to adopt more sophisticated models of human behavior. In particular, theories that focus less on morality-laden admonitions about naughty content, and instead those that focus on individual users and their motivations for consuming media.