One hundred and sixty total same-sex pairs were tested. Researchers used four factors when observing these twins to make a determination: extroversion, neuroticism, psychoticism, and the lie scale. They also studied which of the two factors accounted mostly for variances or stability in personality. The twins were studied in the timeframe of four years from the transition of teenagers into adulthood. It was determined that environmental factors “contribute to change in personality” from roughly anywhere from sixty-two to one-hundred percent (Bratko and Butkovic 155). The findings of this study have similar results to previous ones in the correlations of personality and genetic or environmental influences. Researchers concluded that “environmental factors contributed mainly to change in personality” overall (Bratko and Butkovic …show more content…
For example, the United States is primarily an extrovert-dominated country; that is the “norm”. New Jersey is known as an extroverted state in the US in which people have to speak up in order to get what they want, sometimes to the point of compromising common courtesy. In some regions, soft-spoken people are tribe leaders that are well-respected. Cultural differences are apparent when comparing the western hemisphere (United States) to the eastern hemisphere (India, Indonesia, etc.). Researchers “uncovered several distinctive patterns and geographic regularities in personality traits across cultures” (Schmitt et al. 205). Nations in Europe and South America tend to be more revealing than other east Asian nations who embraced traditional values more. African nations are lower on the neurotic scale in part to being less anxious and depressed. A table in the above study “The Geographic Distribution of Big Five Personality Traits: Patterns and Profiles of Human Self-Description Across 56 Nations” shows that “the most extraverted people tended to live in Serbia and Croatia” and “the most introverted resided in Bangladesh and France” (Schmitt et al. 197). The results of this study demonstrated that personality differences can differ geographically although the test works consistently across the