" (2006) The work entitled: "Tracking the Elusive Human, Vol. II: Reading: Type and Genetics from Chapter 13" states the fact that considerable evidence exists that "whatever the biological foundations to introversion and extraversion are, they have a genetic basis." (nd) it is pointed out that the studies of Sheldon "in which the trunk index remain constant are a good indication of this. And they can be complemented by Susan Faber's "Identical Twins Reared Apart'. (nd) it is further related that in 1956 Eysenck "in a study of identical and paternal twins, found that identical twins resembled each other more closely than fraternal twins in extraversion and introversion." (nd)

The work of Caitlin Thoday entitled: "Are First-Born Children Less Extravert than Later-Born Children" explores this area of study and reports the development of a questionnaire that was designed specifically for testing extraversion/introversion as dimensions of personality. Thoday explains: "Extraversion refers to a tendency to be sociable, active and willing to take risks. Introverts, who score at the low end of the extraversion scale are characterized by social inhibition, seriousness and caution." (nd) the study reported by Thoday relates that "results were collected in conjunction with demographic characteristics in order to test the stated hypothesis. Data was gathered through the self-completion of questionnaires by random sample of 100 respondents." (nd) After conducting statistical analysis of the results the conclusions of Thoday's report states that "extraversion/introversion and birth order are unrelated within the given sample." (nd)

The work of Tracy Ksaizak (2002) entitled: "Relationship Among Birth Order, Perceived Parental Expectation and Personality" reports a study that examined "the correlations between birth order and personality traits as predicted by Walter Toman in 100 Miami University Students." (Ksaizak, 2002) the work of Walter Toman (1969) states that research led him to theorize that particular personality traits are found in individuals in accordance to their order in birth. Oldest children, according to Toman:

Similar to their parents

High academic achievers

Are more often leaders

Are pushed harder by parents

Are often perfectionist

Were often disciplined as a child

Have above-average verbal ability

Are independent

Are serious

Are often tense

Tend to be conservative

Receive a lot of attention

Receive a lot of parental support

Are more comfortable around adults

Accept authority

Mature early

Are abstract thinkers

Tend to expect a lot from life (1969)

Toman states of youngest children:

Tend to be different from their parents

Tend to be low academic achievers

Are more often followers

Are often laid-back

Are not pushed hard to excel

Were not often disciplined as a child

Have average verbal ability

Are dependent

Are often hedonist

Are often rebellious

Tend to be liberal

Tend to be most social and popular

Tend to be most athletic

Are more comfortable around peers

Resent authority

Mature late

Are concrete thinkers

Tend to be optimistic (1969)

Ksaizak relates that Alfred Alder, "a Viennese psychology...established one of the first theories of birth order. His theory focused on 'dethronement'. A couple's first child is like a little prince or princess; subsequent children 'dethrone' this child by taking away parental attention and affection. The effects of 'dethronement', or lack therefore in the case of only children, determine such personality traits as responsibility, attitudes toward authority, self-esteem, and achievement motivation." Ksaizak reiterates his theory that "Oldest children are significantly different from younger children because the first-borns suffer the effects of enthronement while the youngest children do not. Only children possess the characteristics held by first-borns before their "dethronement" occurred, and middle children hold completely different characteristics because they never had the experience of full parental attention before "dethronement." (2002) Dr. Kevin Leman known well for his "Birth Order" psychology holds that the primary constructs of the individual's personality develop and are derived from the individual's birth order within a family. Leman states: "people are the way they are" on the basis of their birth order within their family. "...if you were a first born child you are a much different person than you would have been if you had been born later. If you are a later born, realize alot of things would be different and so would you had you been born first." (2000; p. 75) According to Dr. Jerome Kagan on birth order: "The child's ordinal position in the family has its most important influence on receptivity to accepting or rejecting the requests and ideas of legitimate authority." (Kagan, 1998; p.98) it is noted in the work of Sanderson and Sanders (2002) entitled: "Factors Associated with Perceived Paternal Involvement in Child Rearing" published in the Sex Roles: Journal of Research...

Robert N. Bostrom, J. Mark Prather, and Nancy Grant Harrington write in the work entitled: "Birth Order and Communicative Behavior": "Almost all definitions of personality rest on specific social 'acts', and no one act is typically considered to be a sufficient indicator of any given personality by itself. In other words, any personality trait consists of a number of indicators. This multiple 'act' criterion has been fruitfully applied to communicative behavior by Hewes and Haight (1980)." (Bostrom, Prather, and Harrington, 2007) Bostrom, Prather and Harrington state that Hewes and Haight (1980) demonstrated that "...multiple 'act' assessment is both intuitively and statistically desirable. In other words, we should try to find as many of the 'acts' or (or traits) that explain behavior as we possibly can." (Bostrom, Prather, and Harrington, 2007) These authors relate that overlooked in traditional studies of birth order and personality is the variable of "communicative activity." (Bostrom, Prather, and Harrington, 2007) it is stated that the study of Schacter (1959) states findings that "individual's experienced heightened anxiety before the differentials in communicative behavior appeared. Whether the difference in talking was due to anxiety alone or whether a fundamental relationship exists between birth order and communication would seem extremely important." (Bostrom, Prather, and Harrington, 2007) Bostrom, Prather and Harrington conclude their study by stating that: "While many individual characteristics of communicative behavior have been studied intensively in recent years, little is known of their etiology and internal dynamics. We tend to classify communication characteristics as personality "traits" in place rather than examining some of the possible causes of such traits. Birth order is one possible cause that seems to be importantly related to general tendencies to communicate. Early studies of birth order implicated feelings of power, locus of control, and affiliative tendency. In this study, birth order was shown to have important effects on the communicative characteristics of an individual. Specifically implicated are argumentativeness, talkativeness, and apprehension." (Bostrom, Prather, and Harrington, 2007)
SUMMARY and CONCLUSION

It has been acknowledged for several decades that birth order is linked to introversion or extraversion. However, as acknowledged by Bostrom, Prather, and Harrington (2007) the communicative aspect of the birth order is a variable that has not been well studies but that has been found to be a 'key' variable in the determination of an individual's personality type as related to determination of whether the individual is introverted or extroverted in nature. More study is needed in this area of research in order to understand how communicative factors influence an individual's extraversion.

Bibliography

Beck, Emma; Brunet, Katrina L.; and Vospher, Jane (2006) Birth-Order Effects on Facets of Extraversion. Personality and individual differences 2006. vol. 40 No. 5.

Bostrom, Robert N.; Prather, J. Mark; and Harrington, Nancy Grant (2007)Birth Order and Communicative Behavior University of Lexington Kentucky. Online available at http://www.uky.edu/~bostrom/BIRTH12.htm

Cranton, P. & Knoop, R. (May 1995), "Assessing Jung's Psychological Types: The PET Type Check," Genetic, Social & General Psychology Monographs, 121, 2, p. 249

Kagan, Jerome (1998), Personality Development, Gale Encyclopedia of Childhood Adolescence. Gale Research

Leman, Kevin. (2000), the New Birth Order Book, 2nd Edition. Grand Rapids, MI: Fleming H. Revell

Morgan, George G. (2000) the Importance of Birth Order - Along Those Lines 29 Sept 2000. Ancestry Online available at http://www.ancestry.com/learn/library/article.aspx?article=2453

Sanderson, Susan and Sanders, Vetta L. (2002) Factors Associated with Perceived Paternal Involvement in Childrearing. Sex Roles: A Journal of Research 2002 February. Online available at http://findarticles.com/p/articles/mi_m2294/is_2002_Feb/ai_90888982.

Schacter, S. (1959). The psychology of affiliation: Experimental studies of the sources of gregariousness. Stanford, CA: Stanford University Press.

Stein, Henry T. (nd) Alderian Overview of Birth Order Characteristics - Alfred Alder Institutes. Online available at http://ourworld.compuserve.com/homepages/hstein/birthord.htm

The Genetics of Psychological Types (nd) Chapter 13; Tracking the Elusive Human Vol. 11 Type and Genetics. Online available at http://www.innerexplorations.com/psytext/rt.htm

Thoday, Caitlin (nd) Are First-Born Children Less Extravert than Later-Born Children? University of East Anglia, Norwich. Online available at http://www.palgrave.com/sociology/davies/docs/Caitlin.pdf

Toman, Walter. Family Constellation: Its Effects on Personality and Social Behavior. 2nd ed. New York: Springer, 1969.

Birth Order: Extraversion & Introversion