As can be seen from the previous section the data that was collected does not support the hypothesis. This section will examine some reasons why the hypothesis was not correct in this case. According to previous research by Eysenck (1967) extraverts are significantly lower aroused than introverts. This information would suggest therefore that on an EEG recording extraverts should show less alpha activity than introverts. However, according to our findings this is not necessarily the case. Our results imply that there is not a significant difference between the two groups.
Some possible reasons to consider before totally rejecting the hypothesis are the conditions in which the experiment was carried out, the age of the participant and whether the participant was able to totally relax, for whatever reason. Gale has said in his work that there are certain conditions that introverts would not like to be tested under, and likewise for extraverts. This correlates with Eysencks theory, Pervin (1993:287) describes that research carried out by Eysenck showed “extraverts more often chose to study in library locations that provided external stimulation than did introverts.” Therefore in researching it is an important implication that different environmental designs best fit the needs of introverts and extroverts. What we need to consider is if the intermediate level of stimulation condition was met when the participants were being tested.
Each participant was tested in the same room with a maximum of three other individuals present – the director, recorder and at least one of the tutors who was in charge of the practical. Gale suggests having someone else in the room is enough for intermediate stimulation, but is more than one person perhaps one too many, especially for those at the extreme ends of the extraversion scale?
Another point to consider is the age of the participants. Age was not important in this study, but from the table of results that illustrates the age of the participants (included in Appendix 1), we can see that the majority of participants were aged 18 or 19. In other words it is more than likely that they were first year university students. However the spread of age was quite wide, ranging from 16 years to 55 years. Perhaps it would have been better to restrict this experiment with age requirements, for example only first year university students. But then the problem of mature students also arises, so it would seem that the problem of a wide range ages is set to stay.
Another point for consideration is how do you know if each participant was totally relaxed? It is possible that the nature of the experiment was not hilly explained to the participant, and they were in some way worried about it. It is also possible that the participant had something on their mind and it was not a good day for them to be tested. This could be another factor affecting the results – the fact that both participant and students knew in advance when the experiment was to be carried out. There was time for the participant to ‘prepare’ for it, but also time for them to work themselves up too.
Another point for consideration is the reliability of the equipment that was used. In the experiment the electrodes had to be changed due to inaccurate results being recorded, after a number of tries. This upset could also have affected the results, in causing upset to the participant, hut also in making one question the reliability of the equipment. However it is unlikely that everyone would have experienced problems with the equipment.
It is also worth noting that we are only concentrating on results from the first segment of data and perhaps this is not enough to reach an accurate conclusion about the difference in alpha activity between introverts and extraverts. It is possible that the difference between the two means for any of the other segments was significant, and this needs to be looked into before disproving past research.
One other final point to consider is the questionnaire that was used to distinguish between extraverts and introverts. The participants may have taken too long deliberating over answers, so their true personality was not coming through, and they were maybe answering what they thought they ‘should’ be answering and not how they really felt about each individual question. Hence they were perhaps not truthful with all their answers. Another point about the questionnaires is that it is an old questionnaire. It was used in this study because it has been used in all past research relating to this study, but maybe it is too out-of-date? A suggestion would be to use a more up-to-date questionnaire, as times are changing so are people so I feel that we need to use a questionnaire that is more recent
The conclusions drawn from past research are no longer concrete in light of our findings, as they do not support each other. If this experiment was repeated, perhaps in a different setting, the outcome could differ, therefore agree with the work of Gale and Eysenck. The only methodological shortcomings from this practical seem to be the reliability of the equipment (electrodes) and the use of an old questionnaire, all of the reasons, which have already been explained. Another idea which could be examined in further experiments to help improve the reliability of the results, would be to compare all the four stages of testing, and also pre-select the participants and make sure they are well-briefed beforehand on the nature of the experiment.
Some ideas that for further research with regards to personality and brain activity include comparing introverts and extraverts when they are asleep, and compare how their sleeping patterns differ over a set period of time. Another suggestion is to look into the other two main personality types – neuroticism and psychoticism – and compare the electrical activity of the two extremes in each type. In conclusion, there is no significant difference in alpha activity between extraverts and introverts, hence disproving the hypothesis. However more research needs to he done on this topic to confirm our results.