The increase in temperatures will cause more violent crimes and deaths in coming years, according to a study done by an ISU professor.An increase of two degrees Fahrenheit could result in 24,000 more deaths in the United States alone, said Craig Anderson, professor and chairman of psychology. A four degree increase could result in roughly 38,000 more deaths.The theory will be published in this month’s edition of Current Directions in Psychological Science.Anderson said he has researched the effects of temperature on people since 1979, and studies support his theory that warmer weather leads to more violent behavior.”There’s research going back hundreds of years that shows that warmer climate leads to more aggressive behavior,” he said. “The implication is obvious.”In a report issued recently, Anderson said he estimated anywhere from 6.5 percent to almost 10 percent of all assaults will be caused by hot temperature alone.He said he doesn’t believe cold weather triggers as much aggression as warm weather because when a person gets cold, he or she bundles up and hurries out of the weather.On the contrary, a person feels a need to escape when it is hot, often resulting in aggression, said Anderson. “However, there’s plenty of reason to believe that anything that increases discomfort — whether it be cold or hot weather — will result in more violence,” he said.Lori Kuttler, executive director at Partnership for Violence Free Living in Jefferson, Iowa, said she agrees with Anderson’s theory. However, she said extremely cold weather could also trigger violence. “We see a lot more people [abuse victims] in either really hot weather or blizzard conditions,” she said.The reason more violence occurs in colder weather is “because people are cooped up and want to get outside,” she said. Kuttler also said she believed the actual temperature determines how violent the crime is.”I think that the more extreme the weather is, the more violent the crimes committed are,” she said.More violence occurs in the southern states, Anderson said, to further support his theory. “The temperature effect is much stronger in the South,” he said. “I think that culture of violence results from the temperature.”In addition to the social effects global warming could have, Anderson said temperature increases could affect everyone economically.He said experts have predicted warmer weather will cause serious melting of polarized caps, which could cause major flooding on all sea coasts. “If some of these economical things happen, they are going to have a major impact,” Anderson said.One way of reducing violent crime is to be conscientious of the hot weather effects, he said.”When people are uncomfortable and irritable, they should be aware of it,” Anderson said. “I think that the awareness factor could help people control aggressive behavior.”