<a href="/keyword/ryan-devine/" >ryan devine</a> 17197266 Fall, 2004 Psych 2, section 2 The Evolutionary Approach to Psychology In 1859, Charles Darwin published his magnum opus, the result of all his research in the Galapagos Islands, a book called On the Origin of Species. The book suggested an original, and at the time, rather controversial way to look at the topic. He proposed a concept of evolution, a gradual change in physiology of animal species driven by a combination of mutation and &quot;natural selection.&quot; Animal behavior is no different from animal anatomy and physiology, in this respect. Both change slowly through a combination of mutation or innovation and some kind of selective process which rewards good mutations, resulting in a progressive trend in one direction. The relative success of a behavioral pattern is intimately connected with the physiology and anatomy of the animal exercising that behavior. Every kindergartener knows it is &quot;natural&quot; for a tiger to pursue and kill a deer and that it would be absurd for a hedgehog to try such a stunt. The hedgehog just doesn't have the equipment to be a predator. It has evolved to be a slow, burrowing animal, and that's the way it acts. Any hedgehog attempting to behave as a tiger does would be quickly selected out of the gene pool by the harsh mistress that is Mother Nature. Similarly, a tiger attempting to live in a burrow and subsisting on worms and plants would die young. Human behavior is no less connected to our physiological adaptations. In the chapter of Introduction to Psychology which concerns itself with sleep patterns in humans, there is some mention of the evolutionary significance of sleep. The book states that spending a period of the day inactive and unconscious would actually be very useful from an evolutionary perspective (p. 157). Given our heavy dependence on vision, humans are very limited in a dark environment. In fact, our ability to do work at night would have been so compromised in a world without high-quality lighting that we could easily gain no benefit at all from a night spent on some primitive task, and the expenditure of energy required would make such an enterprise not only fruitless, but in fact less productive than a night spent doing nothing. 1 This, the book says, explains the adaptation to sleep at night. We are better off doing nothing than wasting energy staying awake at night and attempting to do something. Yet another explanation for sleep comes from the dangers involved in wandering around a prehistoric world in the dark. A more primitive human, just as reliant on vision as we are today, could encounter many disasters outdoors at night. A nocturnal predator would have had a huge advantage over the hapless, mostly-blind cave-dweller, making the night wanderer easy prey. Sleeping is a behavioral adaptation to keep us out of the action when we're at our worst, so that we don't find ourselves in the belly of a nocturnal carnivorous animal or lying at the base of an unseen drop-off. The work efficiency theory is also evident in the sleep patterns of other species. Bats, for example, are mostly insectivorous. The bugs upon which they prey are primarily active at dusk, because the day is often too hot and the night is often too cold for them to survive. Bats sleep 19.9 hours per day, according to Introduction to Psychology (page 158). Since they can be maximally productive only a small part of the day, they spend the rest of the time asleep, conserving energy. Herbivorous animals get very little sleep by comparison. Sheep and goats, for example, sleep only 3.8 hours per day (Id.). Since grass and other plants are available around the clock, these animals have no reason to sleep very much. If they can be at the top of their game almost twenty-four hours per day (their eye anatomy is far more suited to nocturnal activity than ours), why would they have reason to sleep any more than is absolutely necessary? The book also relates sleep patterns to eating habits. Carnivores' food is a very concentrated source of energy, with fat and protein giving very large amounts of energy for their mass, when compared to plants. As such, the book says, carnivores can eat relatively infrequently, since each meal gives them so much energy (Id.). Herbivores have to stay active and eating a much larger portion of the day, since they have to consume a much greater quantity of their food to get the same energy that a carnivore gets out of one bite. This requires herbivores to keep a much longer activity cycle. Humans are not the only animal to face nighttime hazards. The same nocturnal predators which will happily devour us can just as easily make a meal out of another animal. Because of this, prey animals will spend much less time asleep than predatory animals, due to their greater 2 need for vigilance against attacks. Horses, for example, while formidable in a fight, are generally found in the role of prey in the wild. They sleep only 2.9 hours a day, often while standing. Sleep patterns, however, are not the only example of how our psychology has been influenced by evolutionary necessity. We have many reasons for doing what we do. There are also many sources for those motivations, some of which are easily explicable from an evolutionary standpoint, but no longer make sense in the world as it is today, because their logical causes are no longer present. The tendency to eat whenever food is available is one such example of an evolutionarily important behavior. Early in humanity's history, before the advancement of agriculture had come to the world, people subsisted as hunters and gatherers. They hunted whatever animals were available, supplementing the meat with fruits and vegetables they found in the wilds of the prehistoric earth. Food was scarce. It was therefore important to take advantage of a plentiful food source while it lasted, since our bodies could store any surplus of energy in fat cells. People ate a lot in times of plenty so that they would not die of starvation in times of need. Today, this reflex, however important it may have been in the world before the great advancements in food production that we enjoy today, is not useful. In fact, the eating reflex can be extremely deleterious to our health. On the other hand, some evolutionarily significant motivations are still present in today's world, and the behaviors they cause are still important for success, though the circumstances have changed greatly since humanity developed those motivations. For example, the motivation to do useful things, also called the &quot;work ethic,&quot; would have been incredibly useful in the past. People without the work ethic would have languished unproductive and unprepared, and then found themselves in a lot of trouble when disaster struck. Today, the work ethic is arguably even more important, since many organizations are meritocracies. Someone very willing to work hard and long is far more likely to be successful than someone with no motivation whatsoever. Introduction to Psychology states that people are more likely to be satisfied with their jobs if they can see that they are being productive and making a difference (page 440). This seems to indicate that people with low work ethic feel apathetic because they have never been shown that their job is significant. They are either unaware of the true meaning of their work, or their work is truly without meaning. Naturally, not every job can be enriched and fulfilling. The not-quite-age-old stereotype of a worker in the fast food industry comes to mind. Nevertheless, 3 many jobs could be made more fulfilling by allowing a single worker to be involved with more of the process with minimal effort on the part of management. This would improve those employees' job satisfaction levels, and inspire them to work a little harder. There are many other cases of human psychology being shaped by an evolutionary need early in our species' history. A very pertinent one, in fact, is that of learning and conditioning. Each variety of conditioning can be observed in a situation commonly encountered in a prehistoric earth, and thus intimately related to the evolution of human psychology. Classical conditioning has a lot of relevance to the survival of early humanoids. Many of our behaviors are evolutionarily conditioned responses to a commonly occurring stimulus. In a prehistoric world, people would have had to respond rapidly and decisively to a wide variety of events. Many of the examples given so far in this paper have been related to predation on early humans. Those same early humans would have found it very useful to rapidly and reflexively awaken, fully alert, when some sound associated with the approach of a predator presented itself while the early human was asleep, an excellent example of a conditioned response in the real world. Operant conditioning in evolutionary psychology, however, is an even better example of the evolutionary reason for learning than is classical conditioning. Positive reinforcement and punishment, useful today in behavioral therapy, would have been especially helpful for letting the proverbial cave-dweller know when he or she had done something right or wrong. Say a hunter/gatherer picked and ate a berry of some unknown variety. If the berry was edible, the behavior of eating that variety of berry would be positively reinforced by the sweetness and food value of the fruit. If the berry was inedible or even poisonous, the behavior of eating that variety of berry would be punished by stomach-ache, serious illness, or death (particularly relevant from an evolutionary standpoint), leading to a decrease in the behavior. In this case, the stomach-ache serves as the punishment for the behavior of eating the wrong berry. Here, we must consider the impact of an aspect of social psychology. Of special relevance to the case of the poisonous berry is our ability to predict what will happen if we engage in a certain behavior from observing the outcomes when others engage in that same behavior. If the hapless berry-eater were to drop dead or experience serious discomfort shortly after sampling a new kind of fruit, the others would learn to avoid that particular variety in the future, in a process almost like vicarious operant conditioning. Similarly, if nothing untoward 4 happened to the adventurous fellow, the other earlier humans would learn of the existence of a previously-unknown source of food, and all would benefit. The other two kinds of operant conditioning (negative punishment, leading to omission training, and negative reinforcement leading to escape or avoidance learning) are also relevant from an evolutionary perspective. Negative punishment, the removal of a positive stimulus (such as food), is just as useful as positive punishment for conditioning a behavior. An especially relevant example for human psychological evolution is the commonly-occurring practice of saving food in case of times of drought or famine to come. If people are (or were) wasteful and do not conserve resources, they will be unprepared for periods of shortage of those resources in the future. In the Old Testament, Joseph (of the coat of many colors) was sold into slavery in Egypt by his jealous brothers. While there, he rose to a position as the advisor of the pharaoh, and had a vision of a great drought. He warned the pharaoh of this future event, and thus the people of Egypt avoided a catastrophic famine by creating stores of food during a time of great surplus. While the Egyptians may have avoided the negative punishment in this case, many peoples have been devastated by famine in the past (the Irish, for example) and changed their behaviors as a result (the Irish started growing crops other than potatoes). Negative reinforcement, the removal of a negative stimulus, is another case of learning to reinforce a behavior. Many animals exhibit behaviors enforced in this manner. An especially good example of this kind of learning in the animal kingdom is exhibited as a means of curing digestive trouble (a very common kind of negative stimulus in the natural world). There are many varieties of natural substances used by animals to help with this scenario. Very fibrous foods speed up the processing of digestible matter, helping with constipation and bloating, and even &quot;wash out&quot; intestinal parasites. These behaviors, once tried, were reinforced by the removal of digestive difficulty. Because of this, animals continue them to this day. Human behavior has been tempered by the crucible of natural selection just as strongly as our physiology has. Our psychology has evolved just as significantly as our bodies themselves. Be it the food we eat, when we eat it, and how much we eat of it, the circadian rhythms we follow, the amount we work and when we do it, what gets us working, or our interactions with other people, our software the mental aspect of our existence has been shaped by millennia of punctuated equilibrium. Some reasons for the ways we behave are not yet understood, and many of the causes of the actions we think we understand are controversial. However, one thing about 5 which all scientifically reasoning folk can agree is that a new concept, ideology, piece of music, or behavior, also called a &quot;meme,&quot; the term Richard Dawkins coined in his book The Selfish Gene, is subject to a selective process which weeds out faulty behaviors and ideas the same way natural selection weeds out deleterious mutations. 6