by Angela Lee, Kenyon ’15
As a senior in college, I like to believe that I am not the same person that I was when I first arrived on campus as a freshman. But even more than that, I like to believe that I am not the same person I was my freshman year of high school. We all can recall our elementary school days and wonder why we felt it necessary to cry outside of our kindergarten classrooms for two hours because we couldn’t find the ring we had wanted to bring to school. Nowadays, you would be hard pressed to get me to raise my voice at all in public.
The questions that follow, then, are these: how have I changed, and is it my personality that has changed? Or is it that I haven’t changed at all, and this is just wishful thinking? The field of personality psychology has spent the last twenty years trying to answer questions such as these, and Kawamoto and Endo take a first look at changes in the personality traits of Japanese adolescents in an attempt to broaden the reach of this field outside of Western cultures.
In order to do this, the researchers led a longitudinal study that took place from 1981 to 2010, using the Yatabe-Guilford Personality Inventory. The YGPI includes twelve traits that fall under either Neuroticism or Extraversion, two of the dimensions in the Big Five personality framework. In using this personality inventory, Kawamoto and Endo were able to gather information from a sample group of 3,656 students (male and female) in Japan whose ages ranged from twelve to eighteen years old.
They wanted to see whether these students’ personalities did, in fact, change throughout the six years during which they attended this school. In order to find this, Kawamoto and Endo administered the personality inventory at least once to the entire sample group, and twice to 1,733 of the students measured initially. The students’ average age when they took the test for the first time was 13.23 years, and the average age of the second administration was 15.85 years, which means that about 2.5 years had passed between the first and second administrations.
While the researchers measured changes in levels of Extraversion and Neuroticism, the researchers also used the data collected to analyze the effect of birth cohort and gender on adolescent personality development. They thought that, referring to previous research, Neuroticism would increase during adolescence, especially for the female participants. They also hypothesized that Extraversion scores would decrease throughout adolescence, and that birth cohort would also make a difference in levels of Extraversion.
Kawatomo and Endo found that these students’ personalities did, in fact, change while they attended secondary school. Overall, there was an increase in Neuroticism scores as the students got older. The scores that were linked to Extraversion either stayed at the same level or showed a downward trend. This means that the students as a whole became more neurotic and less extraverted throughout their adolescent development.
However, keep in mind that the study included other dimensions. These researchers also analyzed the data in terms of the time of birth and gender. For example, both of the statistical analyses Kawamoto and Endo ran from the self-reports they collected showed that the female adolescents exhibited higher levels of Neuroticism and were more extroverted than their male counterparts. The study also showed that the male students became more nervous throughout this time period than the female students did.
Another dimension of the study, the effect of birth cohorts on group changes in personality, produced surprising results. The students who were born in later decades were likely to score higher as well as exhibit a larger increase in the traits that were related to Neuroticism. The opposite change was observed with the characteristics that were related to Extraversion; those who were born later started out with lower scores of Extraversion, and became less Extraverted.
This study adds to current research on multiple levels. First off, it uses a Japanese adolescent sample, which contributes to cross-cultural examination of adolescent development. The study also used a number of different statistical analyses such as hierarchical linear modeling and cross-sectional analyses. However, just as with any study, there are limitations. One of these limitations is that only one specific questionnaire (YGPI) was used to measure adolescent personality. Another is that the sample group of students all came from one school. Therefore, although this sample size was relatively large for a single study, the sample itself may not be representative of all Japanese adolescents. Each individual in this sample group also only took the questionnaire once or, at the most, twice, which means that the variation within the individual may not have been as accurate as it would have been if there were more data points per individual. Finally, because self-report questionnaires can have potential error or biases, multiple types of measurements should be used to cross-examine the results.
The jury is out, but what we seem to hear is that whatever the change is, our personalities definitely develop throughout the course of our adolescent years.
Kawamoto, T., & Endo, T. (2015). Personality change in adolescence: Results from a Japanese sample. Journal of Research in Personality, 57, 32-42. doi: 10.1016/j.jrp.2015.03.002