How Siblings Can Be so Different Despite the Same Nature and Nurture

Nature versus Nurture has always been a hot topic in psychology when determining personality. Nature, being the genetic element of natural attributes, and nurture applying to environmental factors, and life experience. However, one always comes to the inevitable conclusion that both factors influence character. Siblings often seem to dispute this ideology. With genetic coding being shared from the same parents, and living in the same home, one would assume that siblings should be inherently very similar. However, case studies and life encounters has influenced me to think otherwise. I will use my own sister and myself as key examples of this. To explain the phenomenon of siblings being so different, there are many other factors when influencing personality. The theories of Freud, Adler, Erickson, and the lifespan paradigm provide insight as to what might make siblings so different, despite the stigma of nature versus nurture.

One cannot assume that siblings are inherently similar due to genetics, or the nature theory. In my own experience, my sister and I always seemed to have fundamentally different qualities, in regards to personality, as well as appearance. "One reason why brothers and sisters are so different is heredity. The first law of heredity is that relatives are similar and the second law is that relatives are different" (Separate Lives: Why Siblings are so Different, Dunn, J. & Plomin, R. pp. 21-22). This is exemplified in the findings of Mendel over a century ago with his pea plant genetic experiments. The development of punnet squares has been the building block of genetic research ever since. Additionally, "heredity contributes more to differences than to similarities between siblings. Fisher noted that genetic relatedness of .50 for siblings rests on the assumption that genetic effects on a trait are additive…particular combinations of genes may have nonadditive (interactive) effects" (Dunn & Plomin, p. 29). Thus, as much as siblings should be genetically similar, they are to just a great extent different. Furthermore, what genes are similar in nature may not influence personality either. "Genes do not code for thoughts, feelings, or behavior…although promising work has been done searching for biological bases of individual differences it is possible to sketch out these bases only in the broadest of senses" (Individual Differences, Revelle, W p. 1). This poses quite the conundrum for the argument of the nature theory, and the almighty chromosome. One would have to explore psychosocial aspects of development to further understand the maturity of character.

Character is influenced even during infancy. Freud founded the ideas of psychosexual development. The way a parent reacts to a child will significantly affect his or her temperament later in life, as the nurture theory suggests. During the first year of life, Freud believed that a child assumes the oral stage. "During the oral stage (less than eight months old) pleasure comes mainly form the mouth lips, and tongue through activities of sucking and swallowing" (An Introduction to Theories of Personality, Herganhahn, B. & Olson, M. p. 40). Freud also founded the idea of fixation; if one were to become blocked at one particular stage in psychosexual development, and then certain attributes would predictably arise. For example, one fixated at the early oral stage, such as an oral-incorporative character, would engage in an abundance of oral activities, such as eating, drinking, and smoking. The image of someone with the personality of "swallowing" anything, such as a gullible person, or just a good listener, would also apply to this fixation. Many noted psychologists disagree with Freud's theories, the claim being that his research was unfounded because his work led him to deal virtually exclusively with upper class older women. However, one cannot completely dismiss Freud, being that his theories have the building blocks of modern psychology. Freud's ideas on character development can give clues as to the true source of personality, beyond the nature versus nurture assumption.

Issues in infancy that help determine personality continue through Erikson's proposal. Erikson's ideology is rooted by psychosocial factors, encompassing biological strengths and weaknesses, unique life experiences, and social and cultural influences. An infant, according to Erikson, needs to learn basic trust rather than basic mistrust. If care is loving and consistent, infants learn they need not worry about a reliable parent. Erikson stated,

The infant's first social achievement then is his willingness to let the mother out of sight without undue anxiety or rage, because she has become an inner certainty as well as an outer predictability. Such consistency, continuity, and sameness of experience provide a rudimentary sense of ego identity which depends, I think, on the cognition that there is an inner population of remembered and anticipated sensations and images which are firmly correlated with the outer population of familiar and predictable things and people. (Hergenhahn & Olson, p. 168).

Therefore, without moving beyond the basic issues of trust and mistrust, one can never become a fully functioning adult. On a side note, as infants, when I inquired of the nature of my sibling and I on the matter of comfort ability when she would leave us for a moment, my mother informed me that my sister did have horribly adverse reactions to her leaving the room as a baby. I, on the other hand, did not display such upset. Whether this means that I passed Erikson's first stage of psychosocial development and my sister did not is not for me to decide. However, it does explore the differences in our character from our beginnings.

Adler had an out of the ordinary view on sibling relationships and the formation of personality. Adler was the initiator of the principles of individual psychology. Freud had condemned Adler in his own time, once friends; Freud believed that Adler had gone over his head when developing his own theory of psychology, a theory that blatantly contradicted his own. However, I believe that Adler spawned other theories on life and development, and should be addressed. Individual psychology is closely related to humanism because of its concern with the positive relationships among humans. It is also related to existentialism because of its interests with questions concerning the meaning of human existence. The foundations of Adler's theory consist primarily of inferiority, compensation, and superiority. In relation to infancy, Adler noted "all humans start life with feelings of inferiority because we are completely dependent on adults for survival" (Hergenhahn & Olson, p. 100). Feelings of inferiority, according to Adler, however, lead one to strive for superiority. It is ones inadequacies that make us compensate for the bad points and accentuate the good. The attitude holds very true for me in my observations of character. As a child, I was quite sickly and weak. However, I was very ambitious, sometimes to a fault. When attempting to walk, I had put such an effort into the endeavor, that I tore two muscles in my stomach, to the point where I needed surgery. Additionally, I found that I compensated later in life for a poor performance in team athletics by becoming an avid participator in karate. My sister, thus, did not share these experiences, and altered our personality in different ways.

Birth order was of fundamental importance to Adler. According to his theory, the youngest child was the worst position to be in. Adler stated the reason for this,

Generally lies in the way in which all the family spoils him. A spoiled child can never be independent. He loses courage to succeed by his own effort. Youngest children are always ambitious; but the most ambitious children of all are the lazy children. Laziness is a sign of ambition joined with discouragement; ambition so high that the individual sees no hope of realizing it (Hergenhahn & Olson, p. 114.)

Without being self-serving, I believe that we have all found ourselves in a position at one time or another when we felt as if the goal was to great to reach, so there was no attempt in trying only to be inevitably forced into failure. As the later-born in my family, I do feel as if I was horribly spoiled, and I had poor academic success until I was removed from my family, and was forced to stand on my own feet. My sister, on the contrary, being the first born of the two of us, was always trying to prove her worth academically, and did not endure any spoiling from my parents, but rather constant pushing to be number one. I found Adler's comments on laziness interesting to note. My sister never has any doubts in her abilities, and always shot for the grandest prize.

Temperament, best described as individual differences in quality and intensity of emotional responding and self-regulation, is often believed to be present at birth. Furthermore, character is alleged to be relatively stable and enduring over time and across situations, and is influenced by the interaction of heredity, maturation, and experience. Naturally, I am unable to recollect what type of a baby I was, and my sister preceded me, so I was unable to observe her actions either. However, an experiment conducted in 1991 by Thomas and Chess whose goal was to categorize infant temperament, made some interesting discoveries that I could apply to my own family. They observed infant reactions to several stimuli, including activity level, rhythmicity, approach-withdrawal level to new stimuli, emotional reactivity, responsiveness to stimulation, and distractibility. The results were intriguing:

'Easy Babies' (40 percent of the sample) showed mostly positive moods, regular bodily functions, and good adaptation to new situations. 'Difficult Babies' (10 percent) displayed negative moods, irregular bodily functions, and high stress in new situations. 'Slow-to-warm-up Babies' (15 percent) resembled the difficult ones but were less extreme; they were moody and relatively unadaptable, but did not react vigorously to new stimuli. Finally, 'Mixed-pattern Babies' (35 percent) did not fall neatly into any of the first three groups (Lifespand Development, Seifert, K., Hoffnung, R. & Hoffnung, M. p. 160).

I was interested in my mother's opinion on how she thought my sibling and I would have been categorized as infants had we been part of the Thomas and Chess experiment. She has often told me how we were as different as could be since the day we were born, and how she often wondered how she could have produced two children who are so dissimilar. She looked over the different state of affairs that the babies had reacted to, and felt that I would have been an "Easy Baby", and my sister, "Slow to warm up." This is interesting to note being that temperament is supposed to remain relatively unchanged as one grows up. Furthermore, perhaps my sister's cold personality that she still maintains today was always with her, and not a development of parenting. It was once believed that mothers caused autism in children via poor parenting. However, it was later believed that, "The mothers' apparent coldness was not the cause of their children's behavioral abnormalities-it was a reaction to it" (The Nurture Assumption, Harris, J. p. 27). Perhaps my mother had nothing to do with forming that reserved element of my sister's personality, although she is far from being autistic, the same reaction principal might apply.

Early childhood is argued to be a very influential time in regards to character. Freud believed that around age two was a time for the anal stage drama. The anal stage consists of when the child must learn to control his or her physiological processes so they function in the accordance with the demands of society. How one exited this stage would be crucial to development of ones future character. I do not believe that neither my sister nor myself became fixated at this stage; however, one can discover some elements of introspection in practically every neurosis. In the later anal stage, fixation may occur on a symbolic level in stinginess, prudence, orderliness, and a tendency towards perfectionism. This anal-retentive character seems to fit my sister perfectly. The preceding anal stage may produce the anal-expulsive disposition, which tends to be flamboyantly generous, or may be creative. This disposition seems to suit myself. However, although Freud's writings border on prose, I do not believe that there is sufficient evidence in his anal ideology to give these character explanations much weight.

Early childhood continues to be a source of character development for Erikson. Autonomy versus shame and self-doubt are the issues Erikson was concerned with for the child between the ages of one to three. "Children can now willfully decide to do something or not. Thus, children are engaged in a battle of wills with their parents" (Hergenhahn & Olson, p. 168). During early childhood, my parents were no longer together, and my mother seemed to want to create the perfect environment that my sister and I did not experience in our youth. My father had been a very assertive parent, "Too Hard parents are bossy and inflexible: They lay down rules and enforce them strictly, with physical punishment if necessary. These are the shut-your-mouth-and-do-as-you're-told type of people" (Harris, J. p. 47). However, my father took this parenting approach not only to my sister and I, his children, but applied it to my mother as well. My mother seemed to try to adopt the coo of the times, the idea of the "Just Right" parent. The idea behind that being having rules, but take into account the feelings and issues of the children, and above all, express a lot of compassion and love. However, whether the "just right" parenting style has any better or worse effect on a child's personality has yet to be proved. What has been noted, however, is that some parenting styles work differently with children of different temperaments.

Childhood poses as many paradoxes to a child's development of personality as any other stage in development. At this stage in life, when a child develops concrete operational thinking, that is, reasoning focused on real, tangible objects. With pre-school and school changing to a main focus in life, a child begins social interactions that may give clues to ones nature later in time. Beyond the anal stage for Freud lies the phallic stage which could occur somewhere between the third and fifth year of life. In my own life, it is hard to apply Freud's theory of penis envy to me and my sister being that my father was unavailable to either of us during that part of our lives. Freud would probably feel that this would have been seriously detrimental to our character and morality. However, fortunately for my sister and I, many modern psychologists due to his limited subjects of research have contradicted his theory on women. One of the reasons my sister and I can never seem to get along after our initial childhood may be a result of my parents divorce. "The origins of a sibling breach often can be traced to childhood…eldest children who are expected to care for younger siblings may feel overburdened and resentful. Children born too many years apart…may never share common interests or developmental stages. For them, slender ties are easy to cut" (Why we Break up with our Siblings, Funderburg, L. p. 72). My sister did take on a parenting role, especially when my mother was forced to work several jobs, and we were often left at home with just each other. Furthermore, being that we are four years apart, my sister never seemed to want to participate in the games of imagination that preoccupied my childhood.

Corresponding with Freud's phallic stage, Erikson developed his theory of Initiative versus Guilt. During this stage in life, the child is increasingly capable of detailed motor activity, refined use of language, and vivid use of imagination. These skills allow the child to initiate the ideas, actions, and fantasies, and to plan future events. Now that the child has already learned that it is a person via the previous stages, the child's new task is to discover what kind of a person he or she wants to become.

A child's initial few years at school can be very significant when determining character. Freud believed that in a child's sixth year to about the twelfth year, latency would occur. At this time, sexual interests would be repressed and displaced to substitute activities such as learning, athletics, and peer group activities. That is, during this stage, libidinal energy would be sublimated.

Once a child does finally reach school age, Erikson believed the conflict of Industry versus inferiority would cross a child's mind, deeply influencing character. Industry prepares a child to look confidently for productive places in society among other people. School is very important in the development of industry, being that survival requires the ability to work cooperatively with others, and social skills are among the important lessons taught within school. Inferiority is the complex developed when a child does not recognize his or her talents and skills. Within my own childhood, I had an easy time in school, a well-balanced life of academics and friends. However, my sister found making friends a challenge and absorbed her life exclusively in schoolwork. Erikson's ultimate virtue of competence resulting in the development of industry certainly still applies to her whether she adequately filled the requirements or not. However, "another danger associated with this stage is that children may later overvalue their positions in the workplace. For such people, work is equated with life, and they thus are blinded to the many other important aspects of human existence" (Hergenhahn & Olson, p. 171). I firmly feel that my sister continues her collegiate environment because she is reaching for her identity as a doctor to avoid other social obligations.

Adler believed that of the many things one must accomplish in a lifetime, one of the most important was a societal task, which requires cooperation with fellow humans. Adler said, "It was only because man learned to cooperate that the great discovery of the division of labor was made, a discovery which is the chief security for the welfare of mankind" (Hergenhahn & Olson, p. 106). I believe that the beginnings of this discovery must be made initially in school.

The search for identity is quite evident when a child reaches adolescence. Hormonal changes occur in the teenager, as well as the development of formal operational thought. This new form of thinking frees individuals from reasoning only about the here and now and allows then to be more fully logical and systematic in analyzing ideas. Freud believed this was the time when the genital stage would occur, when the person from now through adult life would be a realistic socialized adult typically with heterosexual interests leading to marriage and perhaps child rearing.

Adolescence molds the character of an individual. Erikson believed that from about the ages of twelve to twenty one would undergo the transformation provided from the question of identity versus role confusion. This period does not mean that one will actually find an identity, but is more is search of one. However, if one does not leave this stage with an identity, they leave with role confusion, or a negative identity. The quest to find ones identity can sometimes put a strain on a family. "The period of adolescence is marked by physiological changes, in addition to a withdrawal (sometimes estrangement) from the family origin, increased involvement with peers, and an increase in dominance and aggression in both boys and girls" (Biosocial Perspectives on the Family, Booth, A. p. 1026).

The issues of birth order influencing temperament do not end at Adler. It has been argued, particularly by Sulloway, that later-born children are more likely to rebel against the status quo than first-borns. A later study tested the theory of birth order on later civil disobedience. A band of college students who had been arrested during a political demonstration were further prodded for prior criminal arrests and for birth order. "These 'real-world' findings provide support for Sulloway's (1996) thesis. As predicted, later-born were more likely than first-borns to have been arrested, and the effect was not confounded by family size" (Birth Order and Civil Disobedience: A Test of Sulloway's "Born to Rebel" hypothesis. Zweigenhaft, R. p. 625). Interestingly enough, as the youngest in my family, I was, as the research would assume, the one who would always be challenging the status quo, and usually end up in trouble doing it. My sister has always been much more conservative by nature, thus, we, as a family, loosely confirm the study conducted.

When one enters young adulthood, the issues of intimacy versus isolation become prevalent. According to Erikson, "normalcy" for the young adult consists of, to a large extent, being able to love and work effectively; and on this point, he agreed with Freud:

Freud was once asked what he thought a normal person should be able to do well. The questioner probably expected a complicated answer. But Freud, in the curt way of his old days, is reported to have said: 'Lieben und arbeiten' (to love and to work). It pays to ponder on this simple formula; it gets deeper as you think about it…we may ponder, but we cannot improve on 'the professor's' formula (Hergenhahn & Olson, p. 174).

The final task that Adler one should complete in one's lifetime was that of love and marriage. Adler felt a strong connection to the existence of mankind via this process. He felt that one could never be actualized without a strong role in society, and love and marriage played a key role in this process. Adler said, "On his approach to the other sex and on the fulfillment of his sexual role depends his part in the continuance of mankind" (Hergenhahn & Olson, p. 106). Being that our parents were divorced, this may be why we both have difficulty in this area of our lives.

Some scholars see the two-parent family as the fundamental institution of society-the setting in which adults achieve a sense of meaning, stability, and security and the setting in which children develop into healthy, competent, and productive citizens. According to this view, the spread of single-parent families contributes to many social problems, including poverty, crime, substance abuse, declining academic standards, and the erosion of neighborhoods and communities (The Consequences of Divorce for Adults and Children, Amato, P. p. 1275).

However, it is highly debated the influence that parents can have on their children at all. Although what parents teach their children in itself serves a purpose, the content of what children learn may be irrelevant to the world outside their home. As educated people, perhaps my sister and I will break the divorce cycle occurring in our families. However, we may have taken different lessons from our life experiences due to our different personalities.

Adulthood is a time to discover generativity versus stagnation, according to Erikson. One is believed to be an adult between the ages of about twenty-five and sixty-four. If a person had adequately gone through the stages that Erikson has predicted, then one would have developed a firm identity and lived a productive, happy life. The new need is now to spread this wealth of knowledge onto future generations. This may be accomplished by either interacting with children directly or indirectly, or by creating experiences that will enhance the lives of those in the next generation. Although my sister and I have yet to experience late adulthood, I feel that our actions today will influence our encounters to come. Furthermore, as educated people, we may already be anticipating future adulthood on the horizon.

Erikson saw the crossroad at late adulthood into old age being Ego Integrity vs. Despair. Old age may be a trying time with many physical and cognitive changes. Osteoporosis may make an active lifestyle impossible, and sensory, hearing, as well as the senses of taste and smell decline. As we both work towards budding careers, I feel that we may become tied up in work role preoccupation, rather than differentiating our individual egos from it. My sister had already established her career as a pharmacist, however, she felt compelled to pick up her education and continue on to medical school. When asked her motivations for such a serious undertaking, her reaction was ambiguous, however, after long hours of discussion, I feel as if I have discovered her hidden objection to pharmacy. She liked the idea of being a "doctor". She felt that being a doctor gives one power, prestige, and fulfillment to one's identity. Whether this be true or not, my sister may be trying to anticipate her future desires as needing more challenging activities that pharmacy cannot provide. I similarly, keep peering into the future, and have tried to create as many work options for myself as possible so that I can keep reinventing myself. Perhaps we are both trying to avoid the true terms of our egos, by becoming lost in our work roles, and letting them dictate our identity. I hope by the time we reach late adulthood we will have discovered enough about ourselves so that we may recognize ourselves for what we are and accept it. Erikson felt that was the only way to move onward with life.

To conclude, many biological as well as psychosocial factors can determine personality. Furthermore, when two people, such as my sister and myself are raised in the same home, does not mean we could not walk away with completely different experiences. Genetically, we are as separate as we are similar. Birth order affected the way our parents treated us, affecting our character. Diverse reactions to psychosocial dilemmas altered each of us significantly differently. My sister and I have both become adults, whether we are worlds apart. The question that poses us now is not where we want to go today, but where is the destination for tomorrow.