How does this sound as a theory for why yawning is contagious? I liken it to the appendix – it had some importance somewhere in our evolution, but not so much anymore.
You see, people weren’t always as verbose as they are today – but there had to be some forms of communication , both overt and implicit. Overt communications might be a grunt with a point to call someone’s attention to something yonder. Implicit communications might include the yawn.
Right about the time that these were the primary forms of communication, it was also the case that humans, or whatever ancestors to human beings existed, lived in packs. Their survival depended on it, and it was absolutely necessary to remain in sync with the rest of the pack if you were going to enjoy your raw saber-tooth the next morning. This meant that they not only had to travel, hunt, and settle in packs, but they also had to sleep in packs. So, when one cave person got tired and yawned, there had to be some way for the community to come together on the idea that it was time to go to bed. So, as an evolutionary necessity, humans evolved into sympathetic yawners – you yawn, so I yawn, so we can be asleep at the same time, awake at the same time, and take part in our daily activities at the same time.
This, like the appendix, has never left us. Now what was the appendix for again?
Welcome to the Straight Dope Message Boards, lorwayg, we’re glad to have you with us.
When you start a thread, it’s helpful to other readers if you provide a link to the column. In this case, Why are yawns contagious?
Yes, it’s on the front page now, but in a few days it will sink back into the Archives. So, providing a link helps (a) keep everyone on the same page, doesn’t have people repeating what’s in the column; and (b) cut down on search time as people go looking for the column.
No biggie, you’ll know for next time, and, as I say, welcome.
I learned in my zoology class that yawns were contagious for humans about half of the time. I also learned that there was only one other animal that had been discovered to have contagious yawns: the chimpanzee. Their yawns are contagious but 30% of the time. I bring this up only to notice possible evolutionary linkages as lorwayg, since no one seems to be able to figure out (or get grant money to research) the physiological importance.
Wait a minute! I need to stay up & watch for marauding wolves! What’s with this “all sleep at the same time” nonsense!
foolsguinea, I can’t believe you posted that comment.
I am a hopeless, hopeless night owl. So much so that it has affected my ability to keep a job at times. I have been pondering it of late because I was recently laid off from my job that had flexible, telecommuting hours. I am once again facing the horror that is the 8:00 am start time.
As I was mulling over my plight, I started wondering if there was any genetic reason I am like I am. I began wondering to myself if, 5000 years ago, I would have been the night watchman, keeping my people safe from nocturnal marauders!
And then I come and see your post! You have validated my nightowlness.