Many people check their cellphones without thinking about it, and the habit represents a type of automatic behavior, or automaticity, U.S. researchers say. Lead author Joseph Bayer, a doctoral student in the Department of Communication Studies at the University of Michigan, said automaticity, which was the key variable in the study, is triggered by situational cues and lacks control, awareness, intention and attention. \"In other words, some individuals automatically feel compelled to check for, read and respond to new messages, and may not even realize they have done so while driving until after the fact,\" Bayer said in a statement. The study, published in the journal Computers in Human Behavior, involved several hundred undergraduate students who answered a questionnaire asking about their perceptions and uses of various aspects of communication technology. \"Two mobile phone users could use their devices at an equal rate, but differ in the degree to which they perform the behavior automatically,\" said Scott Campbell, associate professor of communication studies. \"Campaigns to change attitudes about texting while driving can only do so much if individuals don\'t realize the level at which they are doing it,\" Bayer said. \"By targeting these automatic mechanisms, we can design specific self-control strategies for drivers.\"