Hans Eysenck described extraversion-introversion as the degree to which a person is outgoing and interactive with other people. He suggested that individual variations in introversion-extraversion reflect individual differences in the neurophysiological functioning of the brain’s cortex (Cervone & Pervin, 2013). He also generated relevant evidence towards there being a biological dimension, which means that introversion and extraversion should be at least somewhat hereditary. Studies of identical and fraternal twins commonly suggest that hereditary does play a major role in accounting for differences between individuals in E scores (Cervone & Pervin, 2013). This is related to my life because I have an identical twin, and although we have similar personalities, we differ in certain traits. Being identical we share about 100% of our genes which means that many of our differences is probably due to experiences that one of us has without the other involved. We shared many aspects of our environment growing up such as parenting style, wealth, culture, education, and community. Even though we are amazingly similar, close friends and family members can still easily tell us apart. Although we share many of the same friends, our own personal interactions we have with these people have shaped us into our own people. Also, after elementary school, we were not always in the same classes so we had different experiences in the way we learned and interacted with others. This means that these non-shared environmental experiences were crucial to developing our own distinct personalities.
To shed light on this on why nature vs nurture plays such a key role in personality development, a group of scientists observed 40 genetically identical mice that were kept in an enclosure that offered a rich