I am not sure if birds do it, bees do it or educated fleas do it, but humans and other animals certainly do it. We all occasionally yawn. As it turns out, scientists have found out that birds, bees and fleas do not do it because only species of higher intelligence yawn.

Before we discuss yawning, let me evaluate your cognitive level by seeing how easily you yawn. Open your mouth wide, inhale deeply and then quickly exhale. Usually that is enough to produce a yawn. If not, repeat the process but this time look at the word “yawn.”

There are many theories of why we yawn. Let me discuss some of them with the hope that you do not find it boring causing you to, well, yawn. Scientists have long thought that yawning is an expression of tiredness, boredom and stress. Recently, researchers have postulated that yawning is also a way to communicate and connect with others. Studies using gorillas and underpaid college first-year students trying to earn a few dollars to buy the latest version of Minecraft have shown that yawning and seeing others yawn is a way to associate as a group.

Years ago, I started doing stand-up comedy in New York City. Eventually after doing many “open mike” nights, I began to get spots at various comedy venues. Too often I was given a slot, as Sinatra once sang, “in the wee small hours of the morning.” The sparse crowd who stuck around, nursing their melting ice cube vestiges of the two-drink minimum, often became unwittingly subjects of one of my experiments. Note: although unwittingly means “without being aware,” a comic should avoid using a word that has both “un” and “wit” in it.

I would grab the microphone and start to perform my routine. Then I would open my mouth wide and make myself yawn, followed by an “excuse me.” Continuing briefly with my material, I would again yawn. Soon I could see some audience members begin to yawn. It was then that I exposed my experiment and did a monologue about the powers of perception. I always closed my set by obviously looking at my watch and saying “well, it’s getting late.” That caused some in the crowd to also glance at their watch as I said “gotcha again” and left the stage.

According to many experts, yawns can be labeled as either contagious or spontaneous. My comedy bit, mentioned earlier, is an example of the contagious type. But you can be alone with no outside stimuli and still produce a yawn.

There are many theories of why humans yawn. In her book “The Dawn of Yawn,” Ida Knapper believes that there are physical reasons why we spontaneously yawn. It might be a way to bring more oxygen to the bloodstream or keep your lungs vibrant. She discounts the theory that yawning just comes from being tired because her research shows that many people yawn upon waking up in the morning.

Contagious yawning appears mainly in domestic dogs, non-human primates and, of course humans. Some experts say that contagious yawning is a way of communicating socially to a group. Many yawning studies have shown that the more you know the person yawning, the greater the chance that you will echo with your own yawn.

If it is true that some people will yawn merely by reading the word “yawn,” well, I hope you made it this far. If you did, here is an experiment to try. While your family and friends are sitting around the Thanksgiving table, let out an audible yawn. If necessary, wait a few minutes and do it again. If the theory of social communication among family and friends is correct, you will witness a series of yawns around the table. Maybe the yawning and the tryptophan in the turkey will cause your relatives to take a postprandial nap. If so, you get first dibs of mom’s pumpkin pie or Aunt Lynn’s warm apple tart topped with Cousin Ben and Cousin Jerry’s Chocolate Peanut Butter Ice Cream.