"There is a tendency for people to say, 'If things are safer, then I will take more risk,' " he added. "It does not have to involve government interventions: Drugs are developed to reduce blood pressure, so people say, 'Okay, I can eat more, and it does not matter if I gain weight, because I can take this pill.'"

Previous research has shown that people drive faster in vehicles that feel safer, attempt to bike on more dangerous terrain when they wear helmets and pay less attention to infants being bathed when the children are in seats that are said to reduce the risk of drowning.