If the latest mass shooting doesn't move you to cry or to protest, that's probably because you may be losing a normal emotional reaction to an event that is growing more common every day, according to psychological experts, who call this feeling densensitization.
"It's this sort of fatalistic acceptance that this is part of our life now and will happen again," said Frank McAndrew, psychology professor at Knox College in Galesburg, Ill., and a columnist at Psychology Today. "We know there will be a next time and it will be some misfit young male that will act out."
McAndrew, who studies aggression in males, says that the human brain is programmed to pay attention to things that are unexpected and shocking. When it comes to mass shootings, however, it seems that they are becoming commonplace.
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"One shooting is a tragedy, 20 is a statistic," McAndrew said. "You start losing your emotional response to it."
Statistics from the federal government and the FBI back up McAndrew.
Over the past 30 years, public mass shootings have resulted in the murder of 547 people, with 476 other persons injured, according to a March 2013 Congressional Research Service report.
Some of the worst acts of violence in U.S. history have taken place within the past decade. Mass killings at Virginia Tech, Aurora, Sandy Hook, Binghamton, Fort Hood, the Washington Navy Yard and a church in Charleston - have taken place since 2007. In September 2014 the FBI released a report confirming that U.S. mass shootings had risen sharply since 2007: From 2000 to 2006, there were an average of 6.4 annually; from 2007 to 2013, the average more than doubled, rising to 16.4 such shootings per year.
In 2015, there have mass shootings in Columbus, S.C., and Baker, La. Last week in Roseburg, Ore., a student in a writing class walked into Umpqua Community College, killed eight classmates and the teacher before killing himself. Police said he had an arsenal of 14 weapons.
As we read these numbers and watch the reports on television, we become numb to the actual event. But this desensitization has consequences for the other parts of our life as well, according to Brad Bushman, professor of psychology and communication at Ohio State University.
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"When you become numb, it can reduce your empathy and compassion for others," said Bushman, who has conducted studies on this phenomena with violent television, movies and video games. "It reduces how often you help others and increases aggression and violence levels because you think it's no big deal. It's not good."
Bushman said there's one thing that we can do to resist this numbness to violence. Turn off the TV. "As the story unfolds we learn more information about what happened, is it necessary for us to consume all of it?" Bushman said.
Bushman says he has run studies with volunteers watching violent videos and found that images have a greatest affect.
"We found that the more senses you involve the bigger your effect," Bushman said. "It's probably better to learn about it in the newspaper or reading about it online than watching it on TV or watching video. It can be more graphic that way."
As for a long term solution to this cultural shift toward desensitization, McAndrew says he's pessimistic about the future.
"I feel helpless about this," McAndrew said. "I understand why they happen, but I'm not sure the prescription. Having less easy access to guns would be helpful. Politically it's not going to happen."