Well, here it is. My final post for my Evolution and Human Behavior class. How did this semester go by so fast? Honestly, at the start of this whole experiment using word press I wasn’t entirely sure how I was going to really “learn” anything. I figured alls I had to do was make a couple blog posts and that would be it. Boy was it so much more than that. This class has taught me so much about both evolution and human behavior and how the two coincide. I’ve learned mass amount about genes, genetics, theories of evolution, all about Darwin, human behavior and the brain in different situations such as distress or happiness. It was super interesting to see what my peers were blogging about too and how each of their topics related to the class. It was also always very cool when a peer of mine and I were writing about the same topics. I could see if we had similar material, or if we took the question two different ways, or see if they found anything interesting about the topic that I may have missed or over looked. I was able to use this class and my blog to learn and write about topics that I felt passionately about, which made it way easier for me to learn because it was something I was passionate about such as genetic screening and Autism. By writing these blogs I was forced to learn about hyper linking, attributing photos, how to set up a blog site and Twitter and I needed to do extensive background research on each topic I posted about. All in all, I learned ALOT more than I thought I would about every aspect of this class. Turns out, I LOVE blogging and researching things that interest me and posting about them to share with the world information I wish I had known earlier. I also love tweeting about things that actually matter, such as politics, the health care system and the Boston Red Sox. I would give this class a 10/10 and highly recommend it to anyone who is interested in biology. I look forward to posting more throughout the summer and my adventures through graduate school on both this blog and twitter. Who knew I would actually end up using something from a class after the class was over? Thanks Dr. Cangialosi!
What is Autism?
Autism, or autism spectrum disorder, refers to a range of conditions characterized by challenges with social skills, repetitive behaviors, speech and nonverbal communication, as well as by unique strengths and differences. Autism is caused by different combinations of genetic and environmental factors. Some children with autism show hints of future problems within the first few months of their life. In other cases, symptoms may not become obvious until 24 months or later. Some children with autism appear to develop normally until around 18 to 24 months of age and then stop gaining new skills and/or start losing skills.
Possible signs of autism in babies and toddlers:
- By 6 months, no social smiles or other warm, joyful expressions directed at people
- By 6 months, limited or no eye contact
- By 9 months, no sharing of vocal sounds, smiles or other nonverbal communication
- By 12 months, no babbling
- By 12 months, no use of gestures to communicate (e.g. pointing, reaching, waving etc.)
- By 12 months, no response to name when called
- By 16 months, no words
- By 24 months, no meaningful, two-word phrases
- Any loss of any previously acquired speech, babbling or social skills
Possible signs of autism at any age:
- Avoids eye contact and prefers to be alone
- Struggles with understanding other people’s feelings
- Remains nonverbal or has delayed language development
- Repeats words or phrases over and over (echolalia)
- Gets upset by minor changes in routine or surroundings
- Has highly restricted interests
- Performs repetitive behaviors such as flapping, rocking or spinning
- Has unusual and often intense reactions to sounds, smells, tastes, textures, lights and/or colors
How much autism is “in the genes?”
One way to control for the effect of genes when doing research is to look at genetically homogeneous groups. A homogeneous group is a group that is all the same or similar. One of the best ways to being to understand what effects genes have and don’t have in certain diseases and disorders is to look at a homogenous group such as human twins.
Recent research in the Journal of the American Medical Association Psychiatry found that the genetic heritability of autism spectrum disorder is high compared with other factors. Heritability is the proportion of this total variation between individuals in a given population due to genetic variation. In this study, the researchers found that 56% to 95% of the effect is estimated to be genetic, according to a study of 258 twins. (Genetic influences on autism are estimated to be between 74-98% according to research by the Medical Research Council in the UK.)
This study used monozygotic and dizygotic twins. Monozygotic twins are identical twins. Dizygotic twins are fraternal twins. By using both types of twins, this allowed the researchers to study pairs of twins raised by their parents in the same household, which allowed researchers to look at prevalence rates of autism while also having pairs of twins exposed largely to the same environmental factors. According to the study, if one identical twin has autism spectrum disorder, the other twin has a 76 percent chance of also being diagnosed with it.
Researchers are aware that genetics are the primary drivers of autism. The issue is that they do not know which genes are. In this study, there were also significants effects from the environment in which the subjects were in, but the effects the environment had were about 1/2 to 2/3 as the genetic effect.
Another small study, published online in the International Journal of Epidemiology earlier in April in the journal International Journal of Epidemiology, found a possible association between the disorder and a father’s epigenetic tags, which help regulate genes’ activity. Doctors can detect epigenetic changes by testing sperm.
What goes on in the brain with Autism?
Autism is said to be one of the biggest mysteries in contemporary neuroscience. It is defined at the behavioral level, and its three hallmark features are known: impaired social interaction, communication difficulties and repetitive behaviors. What’s not clear, says Charles A. Nelson, PhD, is how autism arises and what the brain is like in someone diagnosed with autism, as compared with the typical brain. He and his colleagues are approaching these questions in a variety of ways.
Some of the greatest advances in autism biology have come from studying a handful of rare neurologic disorders that are caused by a single gene and sometimes include features of autism. Four of the best examples are Rett syndrome, Fragile X syndrome, tuberous sclerosis complex and Angelman syndrome. “It’s not that we think of these disorders as being part of autism,” Nelson explains. “It’s that a sizeable number of the kids with these syndromes wind up looking like they have autism.” Although there are different genes that are affected with each disorder, there is some common ground.
In Rett syndrome, which affects primarily girls & is often associated with autism, the affected gene makes MeCP2, which is a protein that dims the activity of many genes in nerve cells that influence synapse formation or function. The absence of MeCP2 causes dendrites, tree-like structures on neurons that receive incoming messages, to contain fewer spines, or spots for synapses to grow. The synapses that do develop do not function normally.
In Fragile X syndrome, associated with autism in at least a third of cases, the problem is somewhat the opposite. The affected gene makes FMRP, a protein that restricts the manufacture of many proteins at synapses. In its absence, dendrites grow wildly and contain more spines. But these spines are longer and thinner than normal, again, a sign of immaturity.
After diagnosis, how do you help children effected by autism learn?
This is my favorite part. Since 2013 I have worked at Hanover Elementary School in Meriden Connecticut where my mom is the principle, while I am home from school. At Hanover, they have a program called the STARS program where they completely change the learning curriculum to better fit their students with autism and various other conditions that may make it difficult for a student to learn in a typical elementary school environment. An example of this is incorporating a sensory room. This video perfectly explains what the STARS program is all about and how many little minds it has shaped and how many lives it has changed for the better. Spread the word about autism awareness today!
Like anything in the scientific world, genetic screening is both praise and critiqued among the human population. Like many things, there are both pros and cons associated with the use of genetic testing. Genetic testing is the sequencing of human DNA in order to discover genetic differences, anomalies, or mutations that may prove pathological.
One of the first important questions that arise while exploring genetic screening is, what do genes even tell us? Genes are the bits of DNA that give our cells their marching orders. They make up who we are at our most basic cellular level. The millions upon millions of cells we are born with play a very important role in our over all health. Our bodies are completely ran by our genes. We inherit each of our genes directly from our parents. Two copies of each gene are passed on from each of our parents to us. Most genes are exactly the same from person to person, but in some instances, less than 1%, there are slight differences in the gene. This is called a gene mutation. A mutation is a permanent alteration in a gene that makes one of your genes different from the same gene in most other people. Some mutations only effect one gene, while others effect multiple. Gene mutations can impact the way our bodies work and survive in many ways.
Mutations can have three different effects. They may:
- be neutral and have no effect
- improve a protein and be beneficial
- result in a protein that doesn’t work, which may cause disease
This is not to say that all mutations are harmful, because that is not the case. There are mutated genes that are unharmful, like the blue eye gene. “Originally, we all had brown eyes,” said Professor Hans Eiberg from the Department of Cellular and Molecular Medicine. “But a genetic mutation affecting the OCA2 gene in our chromosomes resulted in the creation of a “switch,” which literally “turned off” the ability to produce brown eyes.” The OCA2 gene codes for the so-called P protein, which is involved in the production of melanin, the pigment that gives colour to our hair, eyes and skin. The “switch,” which is located in the gene adjacent to OCA2 does not, however, turn off the gene entirely, but rather limits its action to reducing the production of melanin in the iris — effectively “diluting” brown eyes to blue.“Originally, we all had brown eyes,” – Professor Hans Eiberg from the Department of Cellular and Molecular Medicine. “But a genetic mutation affecting the OCA2 gene in our chromosomes resulted in the creation of a “switch,” which literally “turned off” the ability to produce brown eyes.” The OCA2 gene codes for the so-called P protein, which is involved in the production of melanin, the pigment that gives colour to our hair, eyes and skin. The “switch,” which is located in the gene adjacent to OCA2 does not, however, turn off the gene entirely, but rather limits its action to reducing the production of melanin in the iris — effectively “diluting” brown eyes to blue.” As this example shows, having the blue eye mutation is NOT harmful like other genetic mutations can be.
A gene that no longer makes a protein the body needs combined with other factors can lead to diseases like breast or ovarian cancer, these are harmful mutations. Mutations come in two variations: inherited and acquired. Inherited mutations are passed on from one of your parents and they’re present in virtually all your cells. Mutations that occur because of overexposure to the sun or something going haywire during cell division are called acquired mutations.
So where does genetic screening come into play? Like we discussed earlier in the post, genetic testing is a type of medical test that identifies changes in chromosomes, genes, or proteins. The results of a genetic test can confirm or rule out a suspected genetic condition or help determine a person’s chance of developing or passing on a genetic disorder.
Several methods can be used for genetic testing:
- Molecular genetic tests (or gene tests) study single genes or short lengths of DNA to identify variations or mutations that lead to a genetic disorder.
- Chromosomal genetic tests analyze whole chromosomes or long lengths of DNA to see if there are large genetic changes, such as an extra copy of a chromosome, that cause a genetic condition.
- Biochemical genetic tests study the amount or activity level of proteins; abnormalities in either can indicate changes to the DNA that result in a genetic disorder.
Genetic tests are performed on a sample of blood, hair, skin, amniotic fluid (the fluid that surrounds a fetus during pregnancy), or other tissue. The sample is sent to a laboratory where technicians look for specific changes in chromosomes, DNA, or proteins, depending on the suspected disorder. The laboratory reports the test results in writing to a person’s doctor or genetic counselor, or directly to the patient if requested. New born babies tests are done on a small blood sample, which is taken by pricking the baby’s heel. Unlike other types of genetic testing, a parent will usually only receive the result if it is positive. If the test result is positive, additional testing is needed to determine whether the baby has a genetic disorder.
Some benefits of genetic screening are, a positive result can direct a person toward available prevention, monitoring, and treatment options. Some test results can also help people make decisions about whether they want to have children or not. Infant and newborn screening can identify genetic disorders early in life so treatment can be started as early as possible.
Some risks and limitations of genetic screening involve the emotional, social, or financial consequences of the test results. In many ways, having the genetic screening done can put a strain on relationships, leading people to feel angry and or depressed, and a lot of other factors on the emotional level. As for limitations, genetic testing can provide only limited information about an inherited condition. Often times a test can’t determine if a person will show symptoms of a disorder, how severe the symptoms will be, or whether the disorder will progress over time. Another major limitation is the lack of treatment strategies for many genetic disorders once they are diagnosed.
There are many pros and cons when it comes to genetic screening. A large part of genetic screening is being ready for it and being ready for any outcomes that may arise. For many there are good outcomes but there are also many instances where outcomes aren’t what people expected. There are numerous different resources available for people thinking about genetic screening such as counselors, peer support groups and blogs.
Key Words: nature, nurture, behaviorism, determinism, genotype, phenotype
Nature vs nurture is a scientific debate about whether human culture, behavior and personality are caused primarily by nature or nurture. Nature is often times defined as genetic based where nurture is often time defined as environment or experience. Questions that arise in the nature vs nurture debate are ones similar to, why is a person an artist? Because they are instrumentally inclined, or because they grew up listening to music? Similarly, why is a person an athlete? Because they are athletically talented, or because their parents signed them up for little league when they were very young?
Historically, nurture has been referred to the care parents give to children or the environmental factors one is exposed to at young ages. The nature aspect refers to innate qualities. In modern scientific research as well as historical research, scientists have studied twins to determine the influence of biology and genetics on personality traits. In numerous cases, these studies have revealed that twins, raised separately, still share many common personality traits, lending credibility to the nature side of the debate.
The nature vs. nurture debate has been going on for over 50 years. Initially, psychologists were heavily influenced by the theory of behaviorism. Behaviorism is the theory that human and animal behavior can be explained in terms of conditioning, without appeal to thoughts or feelings, and that psychological disorders are best treated by altering behavior patterns. This theory led many to believe that a human personality is heavily attributed to experience and training otherwise known as nature. In more recent years, specialists have been moving more towards the nature aspect of behavior. Evolutionary scientists have been progressing with studies that have been discovering genes for virtually every behavior.
The nature vs nurture debate goes into deep philosophical questions regarding free will and determinism. Determinism is defined as all actions are determined by the current state and immutable laws of the universe, with no possibility of choice. Those who suggest we derive our behavioral patterns from nature imply that we behave in ways which we are naturally inclined, not so much in ways that we choose to behave. Similar to this, the nature side implies that we behave due to our environment and environmental factors we were predisposed to, not ourselves.
I believe the nature vs nurture debate is a false debate because nature and nurture are not two opposing things. Rather, they are two interconnected and interdependent things. A person is a product of both nature and of nurture. Our behaviors arise from both genetic attributions as well as environmental attributions. Not just one or the other. When genetics are combined with environment this is called a phenotype. Instead of trying to separate nature and nurture, I believe that examining human behavior would be much more beneficial while observing an individuals interactions of both its genotype and with the environment. When I was growing up there were numerous factors that effected my behavior. Coming from a family of divorced parents, my behavior did a complete 180 degree spin before and after the separation of my parents when I was 7 years old. Due to the environment that I was in I would lash out on my siblings, rebel against my parents, did not focus in school, barely wanted to be home and developed severe separation anxiety. After time passed I returned back to “normal” behavior but was never the same as I once was before everything happened. This, in my opinion and own experience, was 100% attributed to the nurture factor of the nature vs nurture debate. Of course as a science major I am well aware of all the genetic components that develop behavioral patterns as well. This is just one example of nature and nurture coming together to create a behavioral change.
In conclusion, there are numerous factors that are attributed to someone’s behavior. Genetics, environment, social norms and expectations as well as influence of others are all factors that are combined to create human culture, behavior and personality.
Jealousy is defined as the resentment against a rival, a person enjoying success or advantage, etc., or against another’s success or advantage itself. Jealousy is a normal emotion experienced when two people share a social or personal relationship and conflicting feelings of anxiety, envy, insecurity and frustration arise. There are numerous different types of jealousy. Some examples of these types of jealousy include:
- Sibling rivalry
- Romantic jealousy
- Workplace jealousy
- Platonic jealousy
Since jealousy is a natural feeling that every human being undergoes, a question arises. Has jealousy evolved for certain sexes? Does one sex have certain genes that would predispose them to be more likely to be jealous? Does one sex get more jealous than the other? And if so, which sex and why? This complicated question was explored in a study by Hasse Walum of the Karolinska Institute in Sweden. Walum conducted a study regarding romantic jealousy and compared their findings between men and women. Participants were presented with two hypothetical infidelity scenarios:
- Sexual jealousy: “You suspect that while your boyfriend/girlfriend was on vacation s/he had a one night stand. You realize that even if s/he did have sex with this other person, they will probably never see each other again. How upset do you think you would feel if this happened?’”
- Emotional jealousy: “You suspect that while your boyfriend/girlfriend was on a trip s/he fell in love with someone else. You realize that even if s/he did develop these feelings, s/he will probably never see this other person again. How upset do you think you would feel if this happened?’”
Participants were asked to answer these questions along a 10-point scale, ranging from 1 meaning not at all to 10 meaning extremely.When Walum and his team crunched the numbers they found that women reported higher levels of jealousy in both categories and men and women BOTH scored higher on sexual jealousy than emotional jealousy. These findings made sense to me because when I think of who would be more prone to jealousy in situations, I would think females. However, something that was interesting to me was that men reported a greater amount of jealousy in response to sexual infidelity than to emotional infidelity. These findings square with the theory that men and women differ when it comes to types of jealousy. Those two types being sexual vs. emotional.
When looking at these two situations myself I tried to put it in perspective of current and past relationships I have been in. I have been on both ends of jealousy. When I was the jealous person, and when my boyfriend was the jealous person in the situation. For the vacation situation I pictured myself being on spring break away from my boyfriend or my boyfriend being on spring break away from me. Obviously, temptation is inevitable and is always there. Morally, I would never let these temptations get the best of me. If my partner were to engage in these temptations I am sure I would be reddened with jealousy, as did many of the participants. In this situation specifically, my partner i’m sure would have the same jealous feelings. As for the second scenario, I do not think my boyfriend/past boyfriends would be jealous of this. Obviously, i’m not sure because I am not them, but if I were to never see the other person again i’m sure it wouldn’t be a huge deal. As for me, jealousy would definitely over come me once again. After comparing these two situations I have a better understanding of the research that was conducted and understand the findings a bit more. It is interesting to read about jealousy and speculate about others opinions, and even more interesting to realize your own feelings when dealing with jealousy and comparing and contrasting with other people.
Is true “selflessness” possible among humans? Why are people (sometimes) nice to each other? Why are some people willing to give their lives for others?
Since I was young, being selfless has always been something that my parents have tried to teach me and have instructed me to incorporate into my life and personality. It was described to me in a way that was short, sweet and simple. There are two different types of people: selfish people and selfless people. Selfish people were described as people who only thought of themselves, wouldn’t do much for others and always had their best interest in their agenda. Where as a selfless person nearly always thought of others, did things for others before they did things for themselves, and thought of themselves last. Once I became a little bit older I realized that no one is completely altruistic/selfless. Everyone is selfish at times, but that doesn’t mean that is a bad thing. In my personal opinion, achieving altruism is nearly impossible for humans. I think that as a population we have evolved in the sense that we are more conscious of when and how to be selfless, but that doesn’t mean we always are. Altruism is an extremely interesting and complex concept.
Helping hand Altruism has been thought of as an ego defense, a form of sublimation in which a person copes with his anxiety by stepping outside himself and helping others. (psychology today). In my opinion there can be no such thing as an altruistic act that doesn’t involve some sort of self involvement. A lot of times altruistic acts come from the feeling of pitty or the fear of karma. This is not to say that acts of true selflessness don’t exist, I just find it hard to believe that someone could be a true altruist in every aspect of themselves/ their lives. “Many psychologists and philosophers have argued that there is, in fact, no such thing as true altruism. In The Dawn, the 19th century philosopher Friedrich Nietzsche maintains that that which is erroneously called ‘pity’ is not selfless but variously self-motivated. Nietzsche is in effect agreeing with Aristotle who in the Rhetoric defines pity as a feeling of pain caused by a painful or destructive evil that befalls one who does not deserve it, and that might well befall us or one of our friends, and, moreover to befall us soon. Aristotle surmises that pity cannot be felt by those with absolutely nothing to lose, nor by those who feel that they are beyond all misfortune. In an interesting and insightful aside, Aristotle adds that a person feels pity for those who are like him and for those with whom he is acquainted, but not for those who are very closely related to him and for whom he feels as he does for himself. Indeed, says Aristotle, the pitiful should not be confounded with the terrible: a man may weep at the sight of his friend begging, but not at that of his son being led to death.”
In my opinion a lot of things we do as human beings comes from social expectation. I think that people are nice to each other out of common courtesy. Certain people are nice to each other also because it is the socially correct thing to do. For example, in politics two parties may not agree with one another and their view points but they need to be cordial towards each other because that is what is socially expected of them.
To me there are numerous reasons that people are willing to give their lives for others. I do not think that this decision comes from someone’s aspiration to be altruistic, but for other emotional reasons. For example, if someone they know or love is sick and needs an organ or blood transplant from them, they would do this. Not because they are being selfless but out of compassion and love. People join the armed forces not with the expectations that they are going to die but because they believe it is their duty to their country to do so. In an emergency, for example a house fire, firemen go into the house to save the people trapped inside not because they feel like it would be the selfless thing to do, but because again they believe it is their duty to do so. I think social expectations play a huge role in the reasons as to why people give their lives for others. I think there is a distinct difference between altruism, patriotism, empathy and compassion. They all may present as similar, but every person has a different reason to do what they do. Many times, peoples acts fall under the category of selfless or altruistic, but I do not believe selflessness as a whole was their intention or what they wished to achieve.
What is the “theory of mind?” What evidence is there to support or refute the idea that only humans have the theory of mind?
Theory of mind is the ability to attribute thoughts and mental states, including desires and intentions, to other individuals. The theory of mind refers to our understanding of people as mental beings, each with his or her own mental states- such as thoughts, wants needs or feelings. We use theory of mind to explain our own behavior to others, by telling them what we think and want by voicing our opinions. We also interpret other people’s behavior by considering their thoughts and wants as well. A flaw within the theory of mind is that as humans, we are not mind readers. We may like to be, but we never truly know exactly what someone is thinking based off of their body language or their behavior. Due to this, the only way to know for certain what another human is thinking or wants/needs is to ask them directly. Communication is key in the human race.
An example of theory of mind is being a mother with a newborn or infant child. If you were a mother in a grocery store who walked away from the cart for a moment to get say a bag of chips from the isle next door, and heard a/your baby crying, you would immediately drop the chips and run over to the baby to ensure its safety and well being. You would first see if the baby was still there and then check to see if it is in pain or why it is crying, then comfort it in any way you can to make the crying or yelling cease. Any person, in my opinion, would do this if they heard or saw a baby, child or any other human crying or screaming. As a human, with the theory of mind, you hear the distress call, automatically process it and come up with a plan of action and do whatever you can to help whoever is in need. This, in my opinion, is what sets humans aside from animals. The ability to process, comprehend and understand others thoughts, feelings and emotions and then take them into consideration to alter your own mind set, is what separates us from other animals.
Many researchers believe that this capacity and ability to attribute thoughts is what separates us humans from other animals as well. “Humans acquire theory of mind by about age 4 and it is central to most human behavior”. American Psychological Association. (2000, February 29). Baboons Have Voice And Communication But Not The “Theory Of Mind” To Understand How Their Communications Will Affect Others.
In the article discusses Baboons and communication, researchers studied the behavior of animals in their natural environment. These researches are said to have heard calls of animals separated from their group and what was assumed to be call backs from the group ensuring that they were there to aid the separated animal, were actually just call back from other lost members of the group. Even mother baboons that were being studied that heard these calls as well did not call back to their lost infants when they were lost and called out for help. “Are the mother baboons just unfeeling? No, suggest the Rendalls and their colleagues in their article “Proximate Factors Mediating ‘Contact’ Calls in Adult Female Baboons and Their Infants,” authored by Drew Rendall, Dorothy Cheney, PhD., and Robert Seyfarth, PhD., and published in the March issue of the Journal of Comparative Psychology. What the baboons lack is what psychologists call “the theory of mind,” the ability to recognize that other animals have knowledge, thoughts and feeling apart from their own. This is not to say that animals don’t have feelings or thoughts, it is the expression of these feelings and thoughts as well as interpretation of other animals feelings and thoughts is what they lack.
Over the thousands of years that the human population has existed, the theory of mind is definitely something that we have evolved into having. I do not believe that when we first started out we had a perfect understanding of what each other thought, I really doubt we even had many thoughts in general besides our basic needs (eating, drinking and reproducing). We have evolved as humans in numerous different ways and I think the theory of mind is something much more recent than we think it is.
Before researching this topic I had some preconceived notions about it. In my opinion addictions can stem from numerous different factors. One, of course, being a genetic trait, and another the social environment one is placed in from childhood to adult hood. After researching this topic; I have come to the conclusion that YES our evolutionary history can explain why some people are addicted to drugs and or alcohol.
In an article by Tammy Saah, she explores addiction from the view point of it being a challenge to our survival as a human population. She states that, “drug addiction, although often regarded as a personality disoered, may also be seen as a worldwide epidemic with evolutionary genetic, physiological and environmental influences controlling this behavior”. Drug addiction is thought of as an adjunctive behavior, or a subordinate behavior catalyzed by deeper, more significant psychological and biological stimuli. It is not just a pharmacological reaction to a chemical but a mode of compensation for a decrease in Darwinian fitness. There are 3 main components involved in substance addiction: developmental attatchment, pharmacological mechanism, and social phylogeny including inequality, dominance and social dependence. (Smith)
Evolutionarily speaking, children that receive care that is more erratic may focus more so on short-term risks that may have proved to be an adaptive quality for survival in ancient environments. Additionally, the pharmacological mechanism describes the concept of biological adaptation of the mesolimbic dopamine system to endogenous substance intake, this basically means that our bodies adjust to “feeling good” and associate that feeling with taking these drugs. These factors combined with the influence of social phylogeny create a position for predisposition to drug addiction. They go along with the common belief that many substances of abuse have great powers to “heal”, and that is often the driving motivation for overuse and addiction. Throughout our evolution as a species, medications and treatments have had a huge impact on our success of survival. Without many medications, we wouldn’t be here today. These medications including vaccinations, vitamins and minerals that keep us alive and healthy. Evolutionary perspective shows an intermediate and fleeting expected gain associated with drug addiction correlated with the conservation in most mammals of archaic neural circuitry (Knutson), most often being a falsified sense of increased fitness and viability related to the three components of drug abuse. The chemical changes associated with fitness and viability are perceived by mammals as emotions, driving human behavior.
Positive emotions, such as euphoria and exiciation, motivate towards increased gain and fitness state, whereas negative emotions, for instance anxiety and pain, evolved as defenses by motivating towards managing potential threats or decreases in fitness level. By taking drugs that would increase this euphoria and excitation may have been a reason for people to take drugs, leading to the addiction of not only the positive effects they thought it had on their evolutionary fitness, but on the drugs themselves. Throughout our evolution we have found that certain medications increase our success with survival, which may have lead to why some people are addicted to drugs or alcohol.
Drug use and addiction seem to have been a part of our society since ancient times. Researchers have evidence and reason to believe that the evolution of mammalian brains and psychotropic plants might be related to each other, connected by ancient drug use. Regardless of the possible co-evolution of drugs and mammalian brains, abuse of drugs inevitably causes long-term disadvantages. Drug addiction could be extremely detrimental for any individual, not only because of the various health problems involved, but also due to the fact that it abolishes negative emotions, such as pain, which in turn shuts off basic defense mechanisms against potential threats. While the origins for drug addiction may indeed be genetically founded, abuse is most likely caused by a combination of both external and internal stimuli. Although a person may be pre-disposed to addiction, environmental and emotional stimuli may act as a catalyst towards the state of actual substance addiction.