Tag Archive for Chimpanzees

Is Laughter Unique To Humans?

by  • March 5, 2013 • 0 Comments

We aren’t the only ones to laugh. In fact, it might not be a surprise to learn that other primates laugh such as chimpanzees, gorillas, bonobos and orangutans show laugh-like vocalizations, but you might be surprised to learn that dogs and rats laugh too! Rats emit short high frequency sounds during play or when tickled. The vocalization is so high pitched that humans can’t hear it. The rats have been found to have what is called “tickle skin” which is found on certain prominent areas over the body. Tickling between the experimenters and rats leads to social bonding and the rats are then conditioned to seek tickling.

Dogs laugh as well. The laugh sounds very similar to a pant to the human ear, but with the help of specialized equipment burst of frequencies can be measured to indicate laughing. Just like in humans, the social laugh in dogs initiates play behaviour and decreases stress hormones. In a 2005 study conducted by Patricia Simonet, Donna Versteeg and Dan Storie where one- hundred-and-twenty dogs were measured across stress behaviours including growling, salivation, pacing, barking, panting, cowering, and lunging. The dogs were compared with each other across a baseline and found that when the laugh track recording was played, they showed an increase in tail wagging and displays of play face. They also showed more social behaviour such as approaching and lip licking. It seems therefore that humans aren’t the only ones to benefit from a good laugh!

Most behavioural psychologists agree that animals and humans laugh in a much different way and while we both laugh for social reasons, animals still lack the underlying self-awareness to laugh exactly like we do so in that sense laughter is somewhat unique to humans.

Above: Rats laugh!

Origins Of Laughs And Why Laughing Is Addictive

by  • March 5, 2013 • 0 Comments

Some researchers conclude that laughs are a modification of the fear response which they theorize grew out of an historical warning that danger was near. By this theory, the laugh occurs because our brains are scared or frightened into laughing. This helps to explain why we often come to tears when laughing for prolonged periods, why we sometimes laugh when scared, or when we deal with horrific events such as a death by suddenly laughing, instead of a seemingly more appropriate response.

Strangely as it might sound, laughing is usual for people during periods of stress and uncertainty. We just laugh it off. Other theories say that laugh came about through a relaxed open play face which is similarly observed in other primates. Chimpanzees and Barbary macaques, for example, show a similar breathing sound “ahh ahh ahh.” Laughing in other primates comes from mock fighting, and social play and in humans, it first appears at one to two months of age and happens during tickling or sudden appearance of novel stimuli as in the peek-a-boo game. My son’s first laughs came about through fear. It was the only way we could get him to laugh. Even now, he laughs when startled such as in the peek-a-boo game.

Researcher Robert Provine describes the laugh as a series of short vowel-like notes or syllables, each being about seventy-five milliseconds in duration that repeat at regular intervals separated by about two hundred ten milliseconds. Laughs go something like “ha-ha-ha” or “ho-ho-ho” but never “ha-ho-ha-ho”. We can see other variations though like “cha-ha-ha” or “ha-ha-ho”. Laughs also tend to punctuate points or sentences and rarely find themselves mid sentence. His research outlines even more complexities in the laugh and if you are particularly interested in laugh structure I urge you to seek out his research, it is quite fascinating.

Laughing can become addictive too, since it releases natural pain killers called endorphins which give us a natural high. Thrill seekers such as sky divers, or race car drivers and even runners, and those who exercise regularly, also reap the rewards of the natural endorphin rushes. Endorphins have been shown to be stronger then morphine as a pain killer so activities like mentioned above can become habit forming. Being around people that make us laugh and smile gives us a positive outlook on the world. Similarly, being around people that are consistently frustrated, bring us down, as we empathize with their emotions. Our autonomic nervous system responds to our environments and the people in it which is why it is important to surround ourselves with people that make us feel good. Conversely, we can become the person others seek to initiate positive feelings, so taking the time to make someone laugh can have a huge payoff.

Where Do Smiles Come From?

by  • March 5, 2013 • 0 Comments

The polite smile is used with people we only know in passing or not at all. The teeth are shown and the lips are curved upward modestly.

The polite smile is used with people we only know in passing or not at all. The teeth are shown and the lips are curved upward modestly.

Research on smiles has been a hot topic since its one of the facial features that is so prominent and important day-to-day. But what purpose do facial expressions serve overall if only to make others aware of our inner thoughts and feelings and perhaps betray us to our enemies? Surely our expressions could be used against us, for the benefit of others, especially given the fact that we often paint our faces with emotion easily and sometimes with abandon.

One theory says that facial expressions are a bit of a chicken and the egg type of situation where it is the expressions we make that in fact control our moods, rather than having our moods influence our expressions. In other words it might be that we give off facial expressions not because we feel happier, but because it helps us to feel happy. This implies that facial expressions are more gear to help those that hold them instead of those who view them and that smiling rather than indicate happiness actually creates happiness. Some of the research does tend to support this finding. When subjects were asked to fake smiles in research studies they tended to be more able to hold positive emotions rather than negative emotions so it seems that our minds are emotionally hardwired to mirror expressions that show up on our face.

We can see how a fearful expression might evolve into a full grin in this image.

We can see how a fearful expression might evolve into a full grin in this image.

Many biologists think smiles have roots as a fearful gesture, as a sort of “fear grin.”  Today though, human smiles are a universally submissive gesture but they can also symbolize pleasure, amusement, aggression, or anxiety (grimace). These other emotions never truly supersede the most common purpose of the smile which is to show submission. We will see this occur over and over again as it applies to smiling. Even pleasure must happen with or around people we feel we can submit to. Smiles are our way we to show that we are non-threatening and wish to maintain peace.

Chimpanzees, like humans have two common sets of smiles. One is a playful smile and the other is an aggressive smile. Humans, when aggressive, will display with a smile by pushing forward their lower lip and baring their lower teeth. This is turn induces either an appeasement or submissive smile in our counterparts or more aggressive body language possibly leading to a battle.

A genuine smile puts us at ease and builds trust.

A genuine smile puts us at ease and builds trust.

A friendly smile, on the other hand, occurs by pulling the corners of the mouth upward which may or may not include crow’s feet as we have seen. Those that lack smiles altogether or who smile infrequently are much more dominant and want to be seen as such. The grimace happens in situations where one is forced to talk or debate under a stressful situation. You will find that this sly face appears almost universally even though no pleasure is felt. The grimace is a disarming gesture meant to appease others, but it usually comes off as insincere and smug. We will see this face under high stress situations. To see this face authentically, pay close attention while watching courtroom television shows. Usually the defendant who is under stress will seem to beam with light from their teeth. The judge will often see him or her as being defiant, and often requests for them to remove their smug look whereas, in fact, no smugness is present at all. In this context a big smile is linked to stress from outside forces, and does not indicate either happiness or smugness. Regardless of the meaning of the specific smile, researchers have concluded that the smile is innate and not learned since even people born blind smile to display happiness.