Heredity_and_Hormones

Checkpoint: Heredity and Hormones Bonnie Giese BEH/225 October 21, 2010 Kathy Dorch Checkpoint: Heredity and Hormones What role does heredity and hormones play when attempting to explain human behavior' One may be surprised to know that heredity and hormones are the main triggers for the way we act. “We are shaped by life experiences and how we react to those experiences can be traced back to hormones and our family histories. Both nature and how we were nurtured affect human behavior” (Hernandez, C., 2010). Genetics “Genetics is the study of how living matter passes down traits from one generation to the next” (Morris & Maisto, 2002, p. 79). Offspring are not an exact replica of their parents, but, there is scientific proof that certain material will pass down from parent to offspring for continuous generations (Morris & Maisto, 2002). This material that is passed down is called genes. Genes consist of genetic makeup called DNA. “Genes are carried by chromosomes which are tiny threadlike bodies found in the nucleus of all cells. Chromosomes vary in size and shape and usually come in pairs. Each species has a constant number: Mice have 20 pairs, monkeys have 27, and peas have 7. Human beings have 23 pairs of chromosomes in every normal cell. The exceptions are sex cells, which have only half a set of chromosomes. At fertilization, the chromosomes from the father’s sperm link to the chromosomes from the mother’s egg, creating a new cell called a zygote. That single cell and all of the billions of body cells that develop from it (except sperm and ova), contain 46 chromosomes, arranged as 23 pairs” (Morris & Maisto, 2002, p. 79). The DNA molecule is the only molecule in living matter that can copy and replicate itself (Morris & Maisto, 2002). DNA contains information such as eye color, hair color, and even height. With DNA come both recessive and dominant genes that will determine what traits will be passed down to offspring and what will likely not pass on (Morris & Maisto, 2002). The combining of genes ultimately make up the physical appearance of an individual. However, genes also can determine a person’s psychological health and the way they act. “[Genes by themselves do not determine how a person will act, but they do influence how our nervous system develops and functions]” (Morris & Maisto, 2002). Because of this factor, the likelihood of developing psychological disorders is much higher within a family who has this type of medical history than that of a family who doesn’t suffer with any psychological illnesses (Morris & Maisto, 2002). In addition, it is also imperative to remember that just because a person is mentally ill; it does not mean their offspring will also be subject to it, it just means they are at higher risk (Hernandez, C., 2010). There is no exact gene to pinpoint where behavioral traits come from. Scientists believe traits and environment are the primary reasons why people act the way they do (Hernandez, C., 2010). Hormones and the Endocrine System Hormones are the primary role in growth, development, reproduction, and metabolism (Hernandez, C., 2010). They are also a main contributor in how humans behave and the moods they exhibit. “[Hormones are released through the endocrine glands. These glands release chemicals known as hormones into the body stream and flow throughout the body]” (Morris & Maisto, 2002). Hormones carry messages to the brain. Hormones are important to understanding behavior because they arrange the nervous system and they affect a person’s reaction to stress, how they sleep, concentration abilities, and sexual behavior (Morris & Maisto, 2002). In addition, hormones affect a person’s mood dramatically (Morris & Maisto, 2002). The thyroid gland produces the hormone thyroxin. Thyroxin balances a person’s metabolism, which in turn determines how active and energetic a person will be (Morris & Maisto, 2002). If a person has a too high of a level of thyroxin, they can develop a troubled attention span, insomnia, fatigue and can become easily agitated (Morris & Maisto, 2002). On the other hand, if the thyroxin level is too low, a person’s craving to overly sleep will be present. Therefore, making the person come lethargic, this can lead to depression (Morris & Maisto, 2002). The parathyroid controls how excited a person will become. The pineal gland releases the hormone melatonin. Melatonin helps to regulate the cycles of sleep and also the times we are awake (Morris & Maisto, 2002). The pancreas releases the hormones insulin and glucagon which are responsible for regulating the body’s blood sugar. If a person’s blood sugar gets too high or too low, they can feel shaky, tired, and develop a “cranky” mood (Morris & Maisto, 2002). The pituitary gland produces a vast amount of varying hormones. It regulates the other glands in the body and is ultimately responsible for how a person reacts sexually, demonstrates interest, and overall, exhibits moods (Morris & Maisto, 2002). Now, we come to the gonads. Gonads refer to the ovaries in females and the testes in males. Gonads release androgens and estrogens. Both sexes release both of these hormones (Morris & Maisto, 2002). These hormones are responsible for sexual desire, aggression levels, irritability and depression (Hernandez, C., 2010). Finally, we come to the adrenal glands. The adrenal glands produce the hormones epinephrine and norepinephrine. These are responsible for returning the body back to normal from stressful events (Morris & Maisto, 2002). Evolutionary Psychology “Evolutionary psychology analyzes human thoughts, traits, and behaviors by examining their adaptive value from an evolutionary perspective. It has proved useful in explaining many cross-cultural commonalities in human behavior. It has also proved useful in explaining language development, differing sexual strategies in men and women, and depression” (Morris & Maisto, 2002, p. 91). By analyzing and depicting a person’s thoughts and their traits, we can potentially determine why they act the way they do and come into better understanding of the human psyche. With this study come many critics. Debates are constant in deciding a fetus’ fate when it comes to determining and genetic “error”. Concluding Thoughts When it comes to behavior, our psyche and physical body play crucial roles. Although our environment can help determine how we behave, it is ultimately our hormones and heredity that determine the primary personality we encompass for the rest of our lives. References Hernandez, C. (2010). The Effect of Heredity and Hormones on Human Behavior. Associated Content. Retrieved from http://www.associatedcontent.com/article/885111/the_effect_of_heredity_and_hormones.html Morris, C. G., & Maisto, A. A. (2002). Psychology: An introduction (12th ed.). Upper Saddle, NJ: Prentice Hall.