Just who are you sleeping with right now? No, this is not a Playboy or Cosmopolitan survey about your sex life, but rather a question of whether or not your four-legged Lassie (or Rover) is snuggled in bed next to you. One recent survey found that about half of all dog owners allow their dogs to sleep on the bed with them.

Lassie’s chance of sharing your mattress depends upon your age and sex. The highest percentage of people found sleeping with their dogs are single females between the ages of 18 and 34. Nearly 6 out of 10 women in this group allow the dog on the bed. The group with the largest likelihood of booting the dog off the bed are married men over 45 years of age. However, even for this class of people, just shy of 40 percent still sleep with their dog.

Many rich, famous, and powerful people have given their dogs bed privileges. According to information carved on his tomb, the Egyptian pharaoh Rameses The Great had a hound named Pahates with the title "Bed Companion to the Pharaoh." Alexander the Great was known to have rested from his battles sleeping beside his great greyhound, Peritas. Much later, Queen Victoria actually died in bed next to her favorite Pomeranian, Turi. Peter the Great, Czar of Russia, and Frederick the Great of Prussia slept with their Italian greyhounds (Lissette and Biche, respectively). And so it has been with many historically important people.

For most people, having a dog in bed is psychologically comforting. There is a loving companion close at hand, and it keeps you from feeling lonely or insecure no matter how dark the night. From the dog’s point of view, however, there are some potentially unwanted implications that result from this sleeping arrangement.

Psychologists have learned that dogs uphold an almost military pack hierarchy, with the pack leader being the general, and so on down to the lowest ranked individual. The leader (or alpha) dog demonstrates his status by controlling resources and positions of power. Alpha goes where he wants and chooses where he wants to sleep. Usually this will be the highest elevation, which gives him a chance to look down on the others (as if he were a very big dog indeed). Therefore, if you sleep on the bed and the dog sleeps on the floor, you subtly assert your position as pack leader. If you allow the dog onto the bed, however, he has the same elevation as you do, which implies the same power position and equal status. This can undermine your leadership role with the dog and may result in demanding behaviour or even outright disobedience.

There is an additional pitfall. Pack members acknowledge the leader by moving out his way when he approaches. Any animal that does not move is physically bumped out of the way. By being forced back a step or two, that dog, in effect, admits that he is lower in status. A subtle variation of this kind of behaviour is leaning, which is often really nothing more than a passive version of the shoulder bump. A dog that wishes to express its dominance will lean its weight on another dog. If that dog moves, however slightly, it has conceded higher status to the dog doing the leaning. Unfortunately, if our dogs lean on us in bed we may, out of politeness and a wish not to disturb them, move somewhat to give them more room. Again this is a signal that is read by the dog as evidence that they are really higher in status than we are. Thus if you must sleep with your dog, at least force the dog to move when you wish to turn or get more space. This will help to undermine any delusions of grandeur that Rover might be tempted to develop.

Finally, there is another potential problem with having Lassie as a bed partner. The survey also found that 13 percent of the couples studied included a partner who so objected to the dog being on the bed that it had actually become a point of controversy and emotional strain in the relationship. Historically, this was the situation with General George Armstrong Custer. Custer had frequent heated disputes with his wife, Libbie, over the presence of dogs on their bed. It eventually came to the point that she threatened to no longer sleep beside him if it involved sharing the bed with his dogs. They eventually reached a compromise agreement. When Custer was at home the dogs could sleep in the bedroom but not on the bed. In the field, however, Custer shared his cot with his greyhounds Blucher and Byron and the fawn-coloured deerhound Tuck, who died with him at the Battle of the Little Big Horn.

Thus, tread lightly in this matter. Your selection of bed partners can have a powerful influence on your life-even if that additional bed partner has four legs and a tail. ■

Stanley Coren is Professor of Psychology at the University of British Columbia and author of several books on dogs, including How to Speak Dog and Pawprints of History. His website is www.stanleycoren.com