There is no scientific evidence that more men sleep on one of the bed rather than the other. Instead, people have preferences about bed side based upon proximity to a heater, proximity to the door and distance from noises and belongings. One survey in the United Kingdom did indicate that more people in general preferred the left side of the bed to the right.
Research by a British hotel chain shows that most men give up their preferred side of the bed in favor of the side that the woman wants. The study also found that people who slept on the left woke up happier than those who slept on the right side of the bed.