Tag Archive for Primates

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.

Eye Flashes, Eye Widening And Flashbulb Eyes

by  • March 5, 2013 • 0 Comments

Flashbulb eyes - it's how the eyes show excitement.

Flashbulb eyes – it’s how the eyes show excitement.

The eye flash is similar to the eyebrow flash in that they both occur very quickly. In the case of the eye flash it lasts on average for only 0.75 seconds but is easily perceived and is quite obvious. The eye flash is a momentary widening of the eyelids during a conversation to reveal the sclera, or whites of the eyes, with no involvement of the eyelids. Humans are the only primates that have whites around their eyes whereas other ape’s eyes are completely dark. It has been theorized that the whites of the eyes evolved as a means of communication helping indicate eye direction.

The eyeflash when given by a speaker, emphasizes specific words being spoken. The eyeflash can serve to change the meaning of a given word or phrase by putting emphasis on one word over another. It normally accompanies adjectives rather than any other parts of speech, and women use it more often them men. I did however notice Brad Pitt perform the eyeflash repeatedly while in a speaking scene in a movie. I’m not sure exactly sure what his intent of the flash entailed, as it accompanied no talking and it occurred once every few seconds while listening, and to me, it seemed odd. Never-the- less he must have thought it added emphasized to his part in the scene. Of note is when eyebrows start and stop flashing as they indicate attachment and excitement with whatever content is being presented. If eyes suddenly stop flashing then it’s likely that a person is lacking in enthusiasms and commitment for the topic at hand. The eyeflash is also association with raised eyebrows to signal submission. Lowering the eyebrows of course, signals the opposite, that is dominance.

On the other hand, a loving mother will widen her eyes when viewing her newborn baby indicating that she cares for them and within seventy-two hours of birth her child will do the same when she enters the room. Eye widening is a positive nonverbal cue indicating that someone is observing positive stimuli that bring them joy and happiness. Eye widening is another form of gravity defying behaviour that is ubiquitous in showing positive emotions and joy. When true contentment is present the eyes will lack any tension at all and will appear relaxed. The size of the eyes directly indicates how positive someone is about a topic. While making eyes bigger and flashing them means that good thoughts are held, squinting where the eyes are compressed means negative thought are held. The same goes for lowered eyebrows!

The final eye cue is flashbulb eyes, which is done by dramatically opening the eyes as big and wide as possible. The eyebrows usually arch in unison as well to make the eyes appear even larger. The cue is usually done to indicate surprise and positive emotions such as being excited to see someone, or have been given a promotion.

[help! – Brad Pitt’s filmology shows over sixty movies and I can’t figure out which movie he was in when he did the eye flash. I do recall it was an older movie and don’t think he was actively speaking at the time, more listening, and in an alley/dark area of some sort. If you know the movie send it my way!]

Why Sometimes Eye Contact Is Bad

by  • March 5, 2013 • 0 Comments

A 2006 study by Stirling University psychologists found that children who were instructed to avoid eye contact while considering their response to a question had a seventy-two percent chance of answering correctly but only a fifty percent chance of answered correctly when they had not been told to look away. One of the theories advanced to explain this finding suggests that looking at human faces, which are complex and information rich, requires a lot of mental processing and that this might disrupt thinking. So next time you want a child (or anyone) to provide a correct answer, instead of forcing them to be polite and maintain eye contact, allow them the freedom to cast their gaze wherever it might fall so they can better process the information. The research shows that children were justified all along by avoiding eye contact when posed difficult questions.

Eye aversion during complex thought is just one example of why sometimes eye contact is bad. Another says that eye aversion controls hierarchy and many species of animals have evolved eye aversion as a function of appeasement gestures. Primates will use direct stares as part of their threat display which is a precursor to direct physical aggression. Averting the eyes altogether or looking down and away with brief glances in the direction of the aggressor can serve to eliminate an attack response. Eye aversion to reduce physical violence is to the benefit of both parties because it eliminates the chances of serious injury or even death. In most cases the aggressor, having received the signal that he is higher in the ranks, will stop in its tracks and turn away.

Eye aversion is a form of submission and submission is usually all that is desired from most attackers. Simply put, violence is often the byproduct of two individuals who refuse to heed each other’s dominance displays, and of which are naturally fairly evenly matched. When dominance displays include things like strutting, stretching, false charges, chest pounding and so forth can not definitively crown a winner, then the conflict is settled by physical contest. Obviously, the last description could apply to any one species of animals, but it could also apply to people. When neither person backs down, a fight ensues.

Children who avoid eye contact can also avoid being physically abused by other students, although it does nothing to eliminate the problem altogether. It has been said that the only true way to settle a bully down is to give them a bit of their own medicine. Bullies are always trying to pick easy fights to build up their dominance and so tend not to want to fight as much as one would be lead to think. Eye contact between humans and non-humans is also well documented. For example, young children who haven’t yet learned to avoid eye contact with dogs, tend to be attacked more often as the dog perceives the child as an aggressor. By most accounts it is recommended that people avoid direct eye contact when confronted by bears to avoid hostile encounters. Avoiding eye contact switches off the threat response and tells the bear that you do not wish to end the dispute with a physical contest.

In most animal species unwavering gaze is used to display dominance and aggression when it happens between members of the same species. When it happens across species it indicates that a prey has been centered out and the stalk has begun. Looking away and avoiding eye contact is a submissive cue and the least dominant is usually the first one to look away. Knowing this, you can easily test out your own dominance. Just pick a victim and stare directly into their eyes for an extended period of time. Whoever breaks first admits to lower rank. You will see that direct and piercing eye contact lasting any longer than five seconds will create an intense desire to look away. If you find it difficult to stare someone down like this then look at the area just above the eyes, as if the person had a third eye. While we know we aren’t making eye contact, the victim won’t realize the difference. Staring will evoke stress, they will feel prey-like and under attack. Keeping the eyes unblinking or even narrowing them is akin to a predator-prey interaction which will make the dominance display even more powerful. However you decide to experiment, do so at your own risk!

The Mirror Neuron

by  • March 5, 2013 • 0 Comments

When people "jive," they are in agreement and this commonality leads to liking.

When people “jive,” they are in agreement, and this commonality leads to liking. In this photo we see a couple mirroring each other by drinking in unison.

The discovery of the mirror neuron happened by accident at the University of Parma in Italy by researchers Giacomo Rizzolatti and Vittorio Gallese. They were studying the planning and movement activity in monkey brains and found that a specific set of neurons responded when monkeys grasped a peanut while other neurons altogether fired when they ate the peanut. When one of the researchers reached for a peanut to give to the monkey, they observed the monkey’s brain react as if it where the monkey who was reaching for it. They found that the same regions of the monkey’s brain activated whether the action was performed by the monkey or if the action was simply observed by the monkey. The mirror neuron was an important discovery, but one that happened completely by chance.

In follow up studies, the mirror neuron has been directly observed in other primates and even birds. Researchers conclude that it very likely exists in the minds of humans as well. However, the mirror neurons in the human brain are much more difficult to study because isolating single neurons is impossible. In animals, the neuron fires when an animal acts and also when they view another animal act. Studies show us that the neuron therefore fires as if the motion was actually performed, when in reality the movement was merely observed. Similarly, brain scans of human’s show that areas of the brain light up when they view others performing actions. These are the same areas that would light up had the action been performed. Today, it is generally agreed that there is no such single neuron at work, but rather a network of neurons working together making the “mirror neuron” a bit of a misnomer.

The origins of the “mirror neuron” might stem from imitative learning. By observing people performing actions we could pick up skills instead of having to learn the actions all on our own. In other words, mirroring allowed us to learn vicariously which is a much quicker way to learn and also less dangerous. Just imagine having to learn to use a sharp knife or chainsaw having never seen one used, nor what either is capable of doing, either to a tomato or tree trunk. Another possible reason for these class of neurons might be related to empathy and emotion since the neurons might help us connect with others. For example, when we view pictures of people who display happiness, disgust, fear or pain, we react to them as if we had felt it ourselves. This ability to connect with people, even strangers, has an important function in our daily lives since it allows us to build and hold relationships, creates sympathy, and inhibit fighting.

Above: The mirror neuron Part I

Above: The mirror neuron Part II