introversion

In the open office environment, various sources of lowfrequency sound, such as the sound caused by the activities and conversations of individuals, create noise pollution. This could affect the mental and neuropsychological health, physical efficiency, and effectiveness of employees. The present research was conducted with the aim of investigating the effect of exposure to low-frequency sound on the cognitive performance of employees and the role of personality types on the level of sound sensitivity.

In this study, the personality type (extrovert & introvert) of individuals was determined by using the Eysenck questionnaire. The participants in this project performed the complex Stroop test at their workplace and in an isolated room. In the end, by comparing the results of the tests, the hypotheses of the study were examined.

The results showed that the cognitive performance of extroverts and introverts was different and improved before and during exposure to noise, which indicates the Yerkes-Dodson law in the workplace. The results indicate that the concentration and selective attention of extroverts in the workplace are better and higher than introverts.

The sound in the office environment has an effect on people’s cognitive performance and the personality type of individuals as a moderator is effective on the amount of this effect. It is explained that extroverts will perform better than introverts in the workplace.

Exposure to environmental sounds (noise pollution) is a key global public health concern that has implications for health and well-being (1). According to the report of the World Health Organization (WHO), noise pollution has direct and indirect effects on the psychological and physiological health of people (2). As mechanical, irregular, unpleasant, unwanted and unavoidable waves, sound is an important source of physical and mental stress that is known as the most important physical harmful factor in developed and developing countries and it causes disorders in the hearing system (3, 4). The significant impact of sound on human health is a well-known fact (5). The adverse effects of sound on human health are related to various parameters such as sound type, frequency, intensity, pressure, duration of exposure and personal sensitivity to sound (4). In most researches, the effect of sound level is raised and related to sound frequency or low frequency sound (LFN (little research has been done. Low-frequency sound has a frequency range of 20 to 200 or 10 to 250 Hz, and the equivalent level of their sound exposure varies between 51 and 65 decibels, which is caused by the conversation of employees, the sound of the ventilation system, the sound of the telephone, and the sound of equipment such as printers(5,6). Previous studies showed that in open office offices, LFN mainly affects the cognitive performance and mental workload of employees (4). There are several studies that have investigated the effect of internal factors of office environments such as temperature, indoor air quality, light and sound on people's performance and have come to the conclusion that people's cognitive performance is also affected by the factors of the work environment (6). According to Carroll (1993), cognitive performance refers to abilities related to cognitive tasks such as learning, memory, language, problem solving, and reasoning (7). Although sound characteristics such as sound intensity and frequency are the main cause of harmful effects of sound, it is of particular importance to pay attention to the characteristics and personality traits of people as hosts of effects (8). Studies on the effects of noise on performance indicate that noise may cause some job problems and the number of errors increase work, but these effects depend on the type of sound and the type of work being performed and the personality type of people (5).Considering the mentioned materials and the existing contradictions regarding the effect of sound on the cognitive performance of people, as well as the effect of personality type on the level of said effect, the upcoming research aims to investigate the effects of exposure to low-frequency sound on the cognitive performance of employees of health, paramedical and Nursing of Kashan University of Medical Sciences and the role of personality types on the amount of effects and accepting or rejecting the existence of a logical and direct relationship in this regard. Considering that previous studies on the effect of sound with different frequencies on people's cognitive functions (especially selective attention and interference time) were conducted under controlled conditions and students were used to perform the test, in this study the effect of sound in the workplace it is investigated on the cognitive performance of employees in real working environments.

This study was conducted among faculty members and staff of health, paramedical and nursing faculties of Kashan University of Medical Sciences. At first, a letter was sent to the staff and faculty members of paramedical, health and nursing faculties of Kashan University of Medical Sciences through the administrative automation system, and the staff of these three faculties were invited to participate in the study. At the same time, and in order to familiarize all personnel with the research plan, the pamphlet introducing the research plan was also distributed among them. After reading the pamphlet and getting familiar with the objectives of the research project, 66 people volunteered to participate in the study by completing the informed consent form.
In order to ensure the health of the auditory and visual systems (full color vision) of the volunteers, audiometry (5) and Ishihara (5,8) tests were performed and 5 volunteers were excluded from the study due to hearing loss.In order to determine the personality type of people (extrovert/introvert), the volunteers were asked to complete the Eysenck personality questionnaire (5). After completing the Eysenck questionnaire by the participants, at first, the answers were checked from the perspective of factor L (reality of the answers), and 18 candidates were excluded from the study due to giving false answers. Then the personality type of the people participating in the project was determined.In order to perform the complex Stroop test (5) in an isolated environment, after 1:30 minutes from the start of work, the volunteers were asked to go to the designated room for the test (isolated room) and perform the Stroop test in that environment. In this stage and the following stages, in order to eliminate interfering factors, the participants were asked to have a full 8-hour sleep the night before the test and to refrain from drinking coffee, chocolate and caffeinated drinks in the hours before the test. Then, in order to determine the effect of the noise of the open-plan office environment on the employees' cognitive performance, on a specific day after 1:30 minutes from the start of work, the employees were asked to perform the Stroop test at their workplace. At this stage, 3 candidates failed to complete the Stroop test and were excluded from the study. Finally, the total number of participants in the research project was 40 people, who were divided into two equal groups of introverts and extroverts according to their personality type. After conducting the Stroop test at the workplace by the employees, by comparing the results obtained from the Stroop test in an isolated environment and the Stroop test at the workplace, the hypotheses of the study were examined. Figure 1 shows the method of conducting this research.

According to the frequency composition of sample population, it is clear that based on observations, %35 of the respondents are men and %65 are women. Among the introverts, 12 people (%60) were women and   8 people (%40) were men, and among the extroverts, 14 people (%70) were women and 6 people (%30) were men. The average age of introverts was 40.75 and the average age of extroverts was 42.4. The average score of personality type in extroverts was 76.45 and in introverts was 23.95. Table 1 shows the comparison of average Interference time 1 and 2 / sum of errors 1 and 2 / Interference number 1 and 2 in the population of introverts. As can be seen, the highest average value is related to Interference time 1 – Interference time 2 with a standarddeviation of 20.57. The results of the statistical test showed that there is a significant relationship between the Interference number of answer 1 and the Interference number of answer 2.Table 2 shows the comparison of average Interference time 1 and 2 / sum of errors 1 and 2 / Interference number of answer 1 and 2 in the extrovert population. As it can be seen, the highest average value is related to the Interference number of answer 1 – the Interference number of answer 2 with a standard deviation of 48.27.Chart 1 shows well the results of the test in the isolation room and the workplace among the introverts and extroverts population. According to the graph, the test results of the two groups of people at the workplace are close to each other. In fact, it can be said that the performance of extroverts in the workplace is better than the performance of introverts.According to diagram 1, the interference time of introverts is longer than extroverts during the test in the isolation room (introverts have responded to the stimulus later and more accurately), and this has caused the number of errors of introverts less than extroverts; Extroverted people have a faster response to the stimulus, and as a result, the number of their errors has also increased, which is in line with Eysenck's theory (5), according to which extroverts act faster than introverts in performing intelligence tests, but Their accuracy is less. It is noteworthy that according to the results of the complex Stroop test at the workplace, the duration of interference of introverts is less than that of extroverts (they responded to the stimulus faster than the time in the isolated room) and the extroverts compared to the time of the test in the room. In isolation, they responded slower to the stimulus, but the number of errors of extroverts was still higher than introverts, which can be a strong reason for the low accuracy of extroverts compared to introverts.According to the results of the present study, the interference time and the number of errors of introverts in the workplace are less than those isolated from extroverts, which are in line with the findings of Jalil Derakhshan et al. (5) in the research of Jalil Derakhshan et al. Introverts performed better after exposure to noise than before exposure to noise, while it was expected that introverts would perform lower than extroverts according to related research. These findings can be explained based on the theory of adaptation; adaptation refers to the gradual adaptation of a person to environmental conditions (5). From the point of view of the interference score factor (the difference between the number of correct responses to the congruent stimulus and the number of correct responses to the incongruent stimulus), which expresses the individual's focus and selective attention, as clearly shown in Figure 1, the performance of extroverts is better than introverts. It is indicative of the higher concentration of extroverts than introverts in the workplace that the results of this study are in line with the results of similar studies. The sound components of attention, tolerance and concentration are reduced. The similar results in this field can be mentioned in Babamiri's research that in introverted people, the problem related to concentration and fatigue in the condition of playing sound is clear compared to the condition without sound(5).

The results obtained from this research show that the sound of the open-plan office (low frequency sound) has an effect on cognitive performance and the individual differences of people (in the present study, personality type) are effective on the amount of this effect in such a way that extroverts at the work place have a higher concentration and selective attention compared to introverts. On the other hand, according to the findings of the current research and the Yerkes & Dodson law, the stimuli of the work environment (presence at an optimal level) can motivate people and increase their performance. During exposure to sound, extroverts have higher cognitive performance components than introverts compared to the time before exposure to sound. The better performance of introverts during the test in the isolation room is an indication of their avoidance of stimulation and their tendency to silence is a natural and genetic issue.
CONFLICT OF INTEREST: The authors declare that there are no conflicts of interest regarding the publication of this manuscript.

Sound is one of the most influential exogenous factors affecting the processing mechanisms of the human brain that play a major role in the occurrence of human errors and occupational accidents. Low-frequency noise is one of the most important sources of noise in the environment, and even at low levels it is annoying and affects people's cognitive performance. Some of the individual differences, such as personality type, hand superiority, neuroticism, and individual sensitivity are factors that influence the effect of sound on cognitive functions. The purpose of this study was to investigate the effect of personality type on cognitive functioning in three situations before, during and after exposure to low frequency noise.

The present study is an empirical basic science. The study population was students of Hamadan University of Medical Sciences through purposive sampling (60 extroverted and 60 introverted). All experiments were performed in the Faculty of Health of Hamadan University of Medical Sciences in a room with controlled acoustic and physical conditions in March, 2016. Eiseng personality questionnaire was used to determine personality type. Simulating the real-world environment of each of the subjects in the industry were exposed to the most intense noise in the industry (50 and 70 dB) for 40 minutes. Each of the subjects underwent cognitive performance in three positions before and during and after the exposure using continuous audiovisual performance test. Environmental conditions were maintained under conditions of thermal comfort and equivalent to a humidified temperature of 18 ° C and relative humidity of 50% without disturbing airflow. Also using fluorescent lamps and halogen lamps of 500 lux with optimum luminance levels were provided and kept constant during all tests. In this study, the recording of industrial ventilation in the workplace was performed using the Cool edit Program software in the frequency band. It is a powerful software for generating sound at different frequencies, especially low frequency sound. When playing the sound, the sound pressure equivalent to the ear of the test subjects was measured and in the sitting position. The sound meter used in this study is SVANTEK Model 971 manufactured by Polish-American Company, which operates according to IEC 61672, which has the capability of analyzing 1/1 and 1/8 octaves. The speakers used in this study are spherical-shaped speakers with a SWA-100 amplifier to amplify the sound at low frequencies that produce a sound similar to the workplace. After each step, the groups were replaced to eliminate the noise exposure effect and to avoid cumulative fatigue in the second level, a 24-hour interval was considered. Data were analyzed by SPSS 20 software and repeated measure ANOVA.

The mean age of the subjects was 23.94 with a standard deviation of 3.25. The distribution of the test subjects was gender uniform and 85% of them were single and the rest were married. Most of the participants in this study were undergraduates of health sciences and 80% of them. The results showed that the cognitive functions of extroverted and introverted individuals were different in the three situations before, during and after exposure to noise. The results indicated that introverts in the pre-exposure condition and extroverts performed better in the exposure conditions. Also, with increasing sound level from 45 to 65 dB, there was a significant difference (p <0.05) between extroverted and introverted individuals 'cognitive functions, which improves extroverted individuals' cognitive functions. The findings also showed a significant relationship between sound and sex.

The findings of the present study provide good evidence for the difference between introversion and extroversion in the tendency to environmental stimuli. The results of this study show that exposure to low frequency noise was influential in the components of participants' cognitive functions There is a significant relationship between the increase in sound level and the components of cognitive functioning with personality type. When exposed to noise, extroverts had higher cognitive performance components. The better performance of introverts in later exposure situations indicates their avoidance of stimulation and their tendency to silence a natural and genetic issue. Accordingly, the effects of personality type should be taken into account in job posts and sensitive occupational tasks that require the use of cognitive functions.

Today, functions of exercise and physical activity in different aspects are hidden to no one. Sports lead to individuals’ well-being and society’s health, create life safety in all physical, psychological, mental, and emotional aspects, etc. and attract the attention of the committed officials in any society. Accordingly, great investments are made in many countries to provide the grounds for every member of the society to be benefited. However, the results of several studies show that many people suffer from multiple injuries and sometimes die as they are doing sports activities. Therefore, sport is one of the high-risk activities with many professional damages that apart from economic costs on the health, include very serious psychological costs on athletes, families in specific and the whole society, in general. Today, it is believed that most of the accidents (about 85 percent) are due to the errors and carelessness of the employees. Therefore, it seems that Improving the safety culture is a basic solution to reduce these accidents in sports events and fields. Safety culture refers to a set of beliefs, motifs, norms, roles and performances that reduce the encounter of employees and managers to dangerous situations. If the governing safety culture in an organization is positive and desirable, this culture, as an effective factor, can commit all elements of the organization to have a major contribution to the safety of themselves and their colleagues. Management is the key element in the safety culture. Management is the key element in safety culture. Managers play a key and essential role in improving the safety culture, preventing accidents and improving job performance and culturalization, and accelerating the process. Among factors affecting occupational performance is the individuals' personality because the individual personality determines his/ her motivation and attitude toward job and the way the individual responds to job requirements. Today, the value of the personality has been accepted as one of the predictors of occupational and behavioral performance.  According to the researchers, unsafe behaviors are highly influenced by individuals’ personal traits because the individuals’ personality traits determine their motifs and attitudes towards their job and how they meet job requirements. Therefore, individuals related to sensitive and safety-related conditions should be highly sensitive to observe safety principles proportionate to their characteristics and consider creating a positive safety culture as an essential issue in sports activities to reduce accidents effectively. Therefore, by identifying and investigating the personality dimensions of sports places managers, it can be used as a predictor of unsafe behaviors.  In summary, paying attention to numerous risks in sports activities is essential and taking safety culture into consideration as a major priority is natural is sports. Considering the role and responsibility of sport field managers in safety and health of athletes, spectators and other visitors, the present study aims at evaluating the safety culture among sport field managers based on IAEA Model and its relationship with their Demographic characteristics and personality. This study aims at answering the following questions: first, how is safety culture among sport field managers? Second, what is the relationship between the positive safety culture and Demographic characteristics and personality of sport field managers (gender, being extroverted or introverted, and experience and education level)?

This is an applied study in terms of purpose, a descriptive survey in terms of data collection methodology, and a correlation study in terms of data analysis. The research population includes all the sport field managers in Iran that consists of 22167 participants according to the statistics of the Development and Maintenance of Sports Facilities of Iran. The sample size included 379 participants based on the table of Krejcie and Morgan. Considering the level of errors due to not receiving complete questionnaires (the questionnaires being lost, not answering them, incomplete and invalid questionnaires), a number of 416 questionnaires were distributed and finally, 400 appropriate and flawless questionnaires were collected and analyzed. Multistage sampling was conducted on different provinces and cities and finally, the sample was selected using simple random sampling. The research tools included Eysenck Personality Questionnaire (EPQ) (1968) and demographic variables including 25 questions and the Safety Culture Survey including 35 questions related to the field of learning and teaching, responsibility, safety priorities, leadership and safety integrity. To insure the face and content validity of the questionnaire, its first edition was investigated by the experts in the field and the required corrections were applied on the items according to experts’ comments. The questionnaires were used after the experts confirmed them. The questionnaires’ reliability was calculated to be 0.76 for the Eysenck Personality Questionnaire and 0.82 for the Safety Culture Survey in a preliminary study by internal consistency through Chronbach’s alpha. Descriptive statistics (frequency tables, frequency percentage, average and standard deviation) and inferential statistics (variance analysis, independent T-test, Pearson’s correlation coefficient and logistic regression) were used for data analysis using SPSS 19 at the significance level of p > 0.05.

Demographic findings of the research showed that the majority of the statistical male sample (68.5%) holds bachelor degree (44.5%) and master degree (29.5%). Results showed that the mean safety culture of sport field managers was 130.12 And its standard deviation was 21.5. The score above 105 is regarded as the positive safety culture. The independent T-test showed that the average score of safety culture is higher in women than men and the difference is significant according to the value of t + -2.970 at the significance level of P = 0.00. Results of ANOVA showed that although by the increase in the work experience, the level of safety culture increases, while no significant relationship was observed between the two variables (P = 0.657). Results of ANOVA showed that by an increase in education level, the positive safety culture increases, while the relationship was not significant statistically (P = 0.391). Eta correlation coefficient showed that there is a significant (P = 0.01) negative (r = - 0.19) relationship between being extroverted and the safety culture. Moreover, there is a significant (P 0.00) and direct (r = 0.29) relationship between being introverted and the safety culture. Considering the type of variables and using eta correlation coefficient to investigate the correlation between the variables, logistic regression was used to determine which variables are strong predictors of safety culture. For overall estimation of the model, omnibus test analysis was used. Omnibus test showed that the logistic regression model was significant. That is, it can predict the variables efficiently. The log-likelihood of logistic regression showed that the variables are 69 percent able to determine the dependent variable. The results of Hosmer-Lemeshow test (HL test) for regression fitting showed that the model is appropriate and fit well. This means that a series of variables have predicted the criterion variable. Therefore, the predictors of safety culture should be identified from among the variables. Results of odds ratio showed that the odd ratio of being introverted and extroverted is relatively good. The odds ratio equals beta (β) in linear regression. The ratio was significant with 0.39 for being extroverted and 0.48 for being introverted. In general, the more extroverted the person is, the safety culture increases and it is vice versa regarding being introverted. In this regard, classification of the average values of safety culture aspects showed that safety priority with an average value of 31.5 and responsibility with an average value of 24.2 had the greatest and smallest average values.

The safety culture is an essential element to prevent accidents from occurring in sports places and events. In the view of researchers, the incidence of unsafe behaviors is greatly under the influence of personality traits of individuals, especially managers. Therefore, the current research aims to investigate the relationship between personality traits of sports places' managers and their safety culture. Results showed that the safety culture has a significant relationship with gender, extroversion, and introversion of managers, but has no significant relationship with work experience and education level. It seems that the more positive attitude of women towards occupational issues, psychological and personality traits, higher sensitivity to job safety issues and avoiding risks that makes them attempt to do the assigned tasks in the best way and the least risks, direct more attention to safety culture in women. In addition, unlike the extroverted people who are risk-taking and in search of excitement do not shoulder their responsibilities and believe that accidents are inevitable, the introverted are indecisive, thoughtful and cautious. The introverted believe that events and accidents are results of their actions and are more satisfied with their actions. Since the introverted are conditioned more and quicker, they adapt to the crowd and obey the rules. They pay more attention to the current rules of safety and follow the rules to develop positive safety culture and reduce unsafe actions. Accordingly, the safety culture is higher in the introverted than in the extroverted. Regarding the lack of effect of education level on mangers’ safety culture, it can be stated that courses related to safety in PE is not taught in higher education in the field of physical education. Furthermore, during in-service courses, the training courses are held similarly for all the people at different education levels and this leads to the irrelevance of the awareness of managers and employees about safety and education level. Therefore, investigating different aspects of personality and safety culture, the efficiency in sports organizations can be improved and the accidents in sport events and fields can be reduced besides identifying and assigning people that pay less attention to safety culture to low-risk jobs.

Disproportion between personality characteristics and the proportion of job dissatisfaction with their jobs, the major challenges that forensic directors in connection with its staff faced. The aim of this study was to determine the relationship between personality characteristics and job satisfaction forensics is Lorestan province in 1393.

This cross-sectional study, descriptive and analytical. Legal Medicine Lorestan Province was studied population of employees. Staff of forensic Medicine Lorestan Province was studied population. Smith and colleagues gauges to measure job satisfaction questionnaire and personality characteristics of Eysenck, which had a total of 61 questions, is used. Data from the study were analyzed using partial least squares method.

The total number of participants (n = 44) were 60% male and 40% female. The correlation coefficient between personality characteristics and job satisfaction was 0/726. The correlation coefficient introverted character, extroverted, stable, neuroticism and job satisfaction, respectively was, 0/231, 0/448,0/ 613,- 0/453.

The characteristics of personality (introverted, extroverted, emotional stability) had relationship with the components of job satisfaction (nature of the work, manager’s behavior, job commitment, payments, citizenship behavior, colleagues’ behavior, promotion and enhancement). But the neurotic personality type there is a significant negative correlation with job satisfaction. As a result, employees who are neurotic are slower than job satisfaction.

The paper presented aims at studying the relationship between internet addiction and introversion among ninth grade female students of Tabriz, district 3.
The study is correlational and descriptive. The statistical population consisted of ninth grade female students which were studying in the academic year 2015-16 who were enrolled in public high schools in Tabriz district 3. The population size was equal to 2566 female students and the sample size was equal to 349 participants who were selected. The sampling method was based on multistage cluster random sampling; the data collection method was based on work field and utilized Eysenck personality questionnaire (introversion, extroversion) and 20-question internet addiction test by Young (IAT). Data analyzed by SPSS software and according to correlation and regression method.
The findings revealed that the relationship between internet addiction and introversion was significant at 30 percent level of certainty (P The results showed that there is a meaningful relationship between internet addiction and introversion among students.

People enter to the learning environment with individual differences in the e-learning, so they are very different from each other in the learning yields assessment. This study aimed to investigate the effect of introversion and the extraversion personality types on the participation of learners in the Moodle learning management system. This causal-comparative study was done on 86 Master of Sciences students in the second semester of law and political science of Allameh Tabatabai University in 2013. The subjects were selected by stratified random method based on Krejcie and Morgan table. They performed some exercises in the cyberspace to the computer acquaintance lesson. The Eysenck (introversion, extroversion) and Rabryka Personality Questionnaire were used. Data were analyzed by SPSS 19 software using independent-T and the Two-way ANOVA tests. No significant difference was observed between girls and boys scores in terms of introvert and the extrovert personality traits, as well as the participation rate. But the mean scores of students’ participation in extroverted and introverted personality traits was significantly different. Interaction between personality trait and the gender was not significant on the level of student participation (p>0.05). In the e-learning environment, introvert subjects more participate than extrovert subjects. In other words, in the e-learning, introvert subjects more participate in the activities and interactions.

Career success is an evaluating and relational concept between someone's current progress and his/her future ideals of occupation. Researchers have shown personality characteristics are one of the main predictors of success and favorable job performance. Thus, the aim of present study was to determine the relationship between extraversion and introversion personality types and subjective and objective career success among nurses of selected private hospitals in Tehran. This research was a descriptive correlational study in which 230 nurses were selected from five private hospitals in Tehran as the study sample through Cochran sampling technique. Proportional to the number of nurses at each hospital, samples were selected via convenient random sampling. Eysenck Personality Questionnaire, Golparvar and Ghazavi career success scale and personal information form were utilized to collect the data. The collected data wereanalyzed by SPSS-19 software using Pearson correlation coefficient and regression analysis. The results indicated a significant relationship between personality type and subjective and objective career success of the nurses. Further, there was a negatively significant relationship between subjective and objective career success and introversion personality type (sig=0/004, r=-0.391 and sig=0.001, r=-0.415, respectively). However, there was a positively significant relationship between subjective and objective career success and extraversion personality type (sig=0.001, r=0.473 and sig=0.001, r=0.545, respectively). It is essential to take into account the relationship between career success and related factors such as personality in the planning, decisions and technical choices. Besides, favorable environmental factors and effective factors such as knowledge, attitudes and cognitive, emotional and behavioral skills, activity level and the situation of the organization should also be taken into consideration.

Background and Personality types are a major factor in deter miring the behavior and mental health of university students and hardiness, as a personal characteristic, affects the resistance of people against stress. This study is conducted on the students of Gonabad Islamic Azad University to find the relationship between three personality types (introversion, neuroticism and psychoticism) and hardiness. Methods and Materials: In this cross-sectional, analytic, bivariate and single-group study, 376 university students were randomly sampled out of the students at Gonabad Islamic Azad University in the fall of 2003. Relevant data were collected by demographic data forms, Ahwas Hardiness questionnaire and Eyserk personality inventory. (including introversion, neuroticism and psychoticism). Findings revealed that the distribution of these three personality types is of significant difference. Also, one-way ANOVA results indicated a significant difference between hardiness and three personality types. Regarding the relationship between the three personality types and hardiness, a well-planned educational program can enhance "hardiness" to a desirable level so that inter personal tension is effectively reduced in various circumstances.