Nowadays, universities play a crucial role in the develop-ment of societies. This role is accomplished through two major functions of universities, that is, instruction and research on scientific and technological and cultural perspectives with the aim of guiding and educating the human resources who make the future of society. Thus, one of the main objectives of the educational systems is meritocracy. If the educational policy of a society remains detached from its culture, civilization history and scientific tradition, it can hardly grow and flourish. The educational system must identify the ideology as well as intellectual frameworks of a society, and make any efforts to relate and comply with them. Furthermore, the educational system in the academic context of a society is inextricably intertwined with culture and civilization spheres of that society (Faraji, 2007).

One of the manifestations of social justice in higher education domain is providing equal opportunities for access to higher education for all classes and strata of society. Fortunately, according to current policies of the Ministry of Science, Research and Technology and with the development of various forms of higher education, such as public, Payam-e-Noor, non-profit, Azad, etc., majority of high school graduates encounter no problem getting admission to higher education. Higher education system in Iran encompasses two major types of education, that is, public and private. Urmia University is among public, tuition-free universities, whereas Payam-e-Noor University, unlike Urmia University is a public, yet tuition-based university, providing non-participatory, distant education. Furthermore, non-profit and Azad universities are private and tuition-based universities which require the students to participate in classes. Despite the availability of equal opportunities for different social classes and strata, the accessibility of equitable educational opportunities in disciplines like engineering, medicine and law – that enjoy a high status due to factors such as providing good income, and playing concrete and tangible roles in meeting basic needs of people – is still open to question. In other words, the question is whether different social classes enjoy equitable access to different types of higher education systems, including different universities (State, Payam-e-Noor, non-profit and Azad) and various disciplines in major academic departments, based on different cultural, social and economic capital. Another question might be whether the social stratification structure of the society is prone to reformulation and intensification through exposure to higher education studies, or the opposite might hold true.

Given the theoretical tenets put forth in the domain of sociology of education, particularly Pierre Bourdieu's views regarding the role of cultural, economic and social capital in academic success and also drawing on the illuminating nature of approaches concerning the relationship between society and education, analyzing the status of admission and presence of students in different educational groups and disciplines in universities and higher education institutions based on the degree of cultural, economic and social capital, and investigating the stratification within higher education based on such factors, are among the crucial problems within the realm of sociology of education, in general, and higher education system, in particular, toward which due heed must be paid.

On one hand, due to the prevalence of controversies and diverse approaches in the domain of sociology of education inequalities,   investigating   this   issue   could answer many questions in this regard, including the would-be relationship between students’ access to academic disciplines and their cultural, economic and social capital? On the other hand, it goes without saying that exposure to education is a key factor in one's choice of career and hence his/her income level. Thus, the educational policies opted for by the society, and consequently access to education, directly influence income and wealth distribution in a society. As such, the equitable distribution of educational opportunities, that is, equal rights for all regarding access to education, is an agreed upon principle underscored by all countries and societies, and it has been noted as a useful means in poverty reduction programs and as a crucial factor in social mobility and equality in society by most policy-makers (Isazadeh, 2008).

Most studies conducted in the area of equal educational opportunity in higher education have focused on access and admission to higher education, and scant research has been allocated to examining and comparing cultural, social and economic capital of students involved in different academic groups and disciplines, and analyzing stratification of admissions within different academic disciplines.

Taking into account what has been mentioned earlier, the overall objective of the present study is examining stratification within higher education through investigating cultural, social and economic capital of the students studying different academic majors across universities.

There are two general approaches regarding the domain of inequalities in education and the relationship between society and education. The first approach argues for the provision of equal opportunities in educational system and contends that inequality is a reality that exists in the community, and that schools and universities are the only institutions that can neutralize its effect, and provide fair opportunities for all individuals (Ahanchian, 2007).

The other approach argues that educational system reproduces the existing inequalities in a community, which are produced, in the first place, through the students who enter educational institutions. Therefore, the social pyramid in a society is not only reversed but also consolidated by the educational system. The proponents of this approach believe that equality of educational opportunity cannot be provided merely by educational rules, and it is the underlying factors such as family, personal, social, economic and cultural issues that may bring about inequality in academic achievement (ibid).

According to Bourdieu and Passeron (1977), the policies aimed at furthering access to higher education in France with the purpose of thwarting the superior position of affluent families  have  all  ended  in  failure,  and  their mere influence has been changing the terms and conditions of the game which leads to obtaining such superior positions. Although financial resources used to be regarded as an indicator of welfare in the past, today the ownership of cultural capital has led to a redefinition of social stratification (Fulton, 1997). Based on the theory of cultural and social reproduction, the characteristics of social structure maintain and perpetuate differently within different time periods (Tavakkol et al., 2010).

Bourdieu is one of the leading theorists of social and cultural reproduction. Economic capital, in his opinion, is comprised of income and other financial resources that appear in the form of possession. Income and assets can be seen as indicators of economic capital. Cultural capital, in his view, is similar to the Weberian concept of lifestyle, which includes specific skills, tastes, styles of speaking and the ways through which an individual is distinguished from others. Bourdieu considers education as a manifestation of cultural capital and refers to the individual’s proclivity toward cultural objects and cultural products’ accumulation as the ‘cultural capital’ (Zhiyanpur et al., 2013). Bourdieu defines social capital, as another type of capital in addition to economic and cultural capital, as follows:

Social capital is the sum of actual and potential resources that result from a permanent network of more or less institutionalized relationships of mutual acquaintance and understanding; a network that provides each of its members with social capital support and renders them creditable (Bourdieu, 2005).

Domestic and foreign studies exploring the impact of cultural, economic, and social variables in families on the probability of access to higher education opportunities for different groups with different socio-economic profiles indicate that there is a positive and significant relationship between the likelihood of being admitted to higher education and parents' educational levels at diverse periods of time. The location of households in urban areas (as opposed to rural vicinities) has had a positive impact on entering higher education, and hence the higher the financial resources and permanent assets of people, the more likely their access to higher education. The comparison of different time periods has revealed that over time a noticeable change has taken place in the likelihood of access to higher education opportunities for more well-to-do families (IsaZadeh, 2008).

In a cross-national study of 13 countries, Shavit and Blossfeld (1993) explored whether expansion of an educational system decreases the gaps in educational attainment of students from different socioeconomic backgrounds. Furthermore, a recent project by Shavit et al. (2007) examines how characteristics of educational systems shape entry into higher education, and particular types of institutions within it. Raftery and Hout (1993) argued  that inequality in educational attainment between different social strata persists unless the privileged group has reached saturation. If saturation is not reached, the privileged group will disproportionately take advantage of new educational opportunities, preserving class inequalities.

Other studies carried out in this regard including the studies conducted by Dehnavi (2003), Gharoon (2003), Khodaei (2008), Jalali (2010), Noorbakhsh (2010), Janalizadeh et al. (2011), Giftymaku (1991), Maslen (1995), Ghasimoghlu et al. (2002) and Kipp et al. (2002) have confirmed that cultural, social and economic capital owned by families has a significant and positive effect on children's achieving high ranks and being admitted to top academic disciplines. However, Noghani (2010) showed that the social capital of a family does not have a significant effect on the likelihood of students’ admission to university, in the presence of factors like economic and cultural capital and students' educational background, and found that family’s economic and cultural status has an impact on their academic performance, regardless of their educational capabilities and aptitudes. Moreover, in another study, Zhiyanpur et al. (2013) demonstrated that students of sociology and industrial designing have the highest level of cultural capital, and that students of law and medicine, in comparison, enjoy a lower degree of cultural capital.

Then, it can seen that educational systems perpetuate the stratification structure through controlling the dominant class, and thereby monitor the access of different social groups to social opportunities. Thus, the educational system perpetuates the stratification system, and prepares the individuals to play roles in the capitalist society (Tavakkol et al., 2010). Accordingly, the stratification of higher education can be defined as better access of particular classes in society to particular disciplines and educational opportunities, due to their better status in terms of the aforesaid factors and because of their inclusion in higher strata of society (Ghasemi et al., 2011).

Based on the issues referred and the theories put forth in the field of educational inequalities, this study sought to examine the status of cultural, social and economic capital of students studying in different academic dis-ciplines, including medicine, humanities, basic sciences, engineering and agriculture. For this purpose, the following hypotheses were formulated and tested:

1. There is a significant difference between cultural, economic and social capital of students majoring in different academic disciplines.

2. There is a significant difference in cultural, economic and social capital of students according to the type of university in which they study (State, Azad, Payam-e-Noor, Non-profit, Medical Sciences).

3. There is a significant difference between the cultural, economic and social capital of students in state and non- governmental universities.

4. There is a significant difference between cultural, economic and social capital of students who attend tuition-based and tuition-free academic systems.

The research method used in this study is field research and descriptive-survey type. For data analysis, the study used descriptive statistics to indicate measures of central tendency and variability. Concerning inferential statistics, independent samples t-test, one-way ANOVA, Mann-Whitney U, Kruskal-Wallis, and Spearman correlation coefficient were run using statistical package for the social sciences (SPSS) software. Owing to the significance levels obtained, it was found that distribution of data for cultural and economic capital variables was not normal, whereas the one regarding social capital was normal. Thus, nonparametric and parametric tests were utilized, respectively, to analyze the data relevant to each of the variables.

Population and sample

The population of the study was composed of undergraduate students majoring in principal academic disciplines of humanities, basic sciences, engineering and agriculture at Urmia state university, Azad University, Payam-e-Noor and Non-profit institutes, as well as PhD and BA/BS students of medicine and related fields from Medical Sciences University in 2014 to 2015 academic year. As it can be seen in Table 1, the number of admitted students in 2012 in the universities of Urmia was 7,462, which constitutes the population of the study. The sample was selected via stratified sampling, through which 438 were selected out of the total 7,462 students.

Instruments

Data collection in the current study was done through administration of three questionnaires of cultural, economic and social capital, organized as one inventory with three sections. Cultural capital and economic capital questionnaires were researcher-made and developed based on Tajasob (2012) and Sameri's (2014) questionnaires, whose validity (both content and face validity) was confirmed by university professors and experts. Moreover, the questionnaire developed by Alizadeh et al. (2013) was used to measure social capital. The reliability coefficients of the cultural capital, economic capital and social capital questionnaires calculated through Cronbach's alpha were 0.82, 0.75 and 0.88, respectively.

Descriptive statistics

Regarding the demographic statistics and in terms of gender, 162 (41.3%) of the students in the study were male and 230 (58.7%) of them were female. Concerning major academic disciplines, 146 (36.7%) of the participants in the study were from humanities, 44 (11.1%) from basic sciences group, 107 (26.9%) from engineering, 54 (13%) from agriculture, 15 (8/3%) from medical department, and 32 (8.0%) of the students were from the fields related with medicine. Regarding the universities with which they were affiliated, 115 (28.9%) of the participants in the study were from Urmia State University, 38 (9.5%) were from the University of Medical Sciences, 93 (23.4) were from Payam-e-Noor University, 86 (21.6%) were from Islamic Azad University of Urmia and 66 (16.6%) were from non-profit institutes in Urmia. Regarding the type of university (public/private), 246 (61.8%) of the participants were from state universities, including Urmia University, Urmia University of Medical Sciences and Payam-e-Noor University, and 152 (38.2%) of the respondents were from non-governmental universities, including Islamic Azad University of Urmia and non-profit institutes in Urmia. In terms of the type of fee (tuition-based/tuition-free), 255 (64.1%) of them were paying tuition fees, and 143 of the students (35.9%) were studying free (tuition-free).

Inferential statistics

Hypothesis 1: In order to examine differences in cultural capital and economic capital of the students of major academic discipline groups, Kruskal-Wallis test was used. As it can be observed in Tables 1, 2 and 3 the lowest level of cultural capital belonged to the basic sciences group and the highest level belonged to the medical students. Also, the highest rank in economic capital belonged to the medical students’ group. As the p-value for both cultural capital and economic capital variables (Table 4) are less than 0.05 (P < 0.5), it can be said that there is a significant difference between  major  academic

discipline groups’ students with regard to their cultural capital and economic capital. In order to examine the differences in social capital among students from major academic discipline groups, a one-way analysis of variance (ANOVA) test was used. As Table 5 shows, the size of the F-value 1.153, with the degrees of freedom of 5 and 359, is not significant at 0.332. Therefore, regarding the social capital of the students, there is no statistically significant difference.

Hypothesis 2: In order to examine the differences in cultural capital and economic capital with regard to different types of universities (State, Medical Sciences, Payame-eNoor, Non-profit, Azad), the Kruskal-Wallis test was used. As it can be seen in Table 6, the lowest cultural capital rank belonged to Urmia State University students and the highest-ranking regarding cultural capital was the Islamic Azad University. Likewise, the lowest rank in economic capital belonged to Urmia State University and the highest rank in economic capital belonged to the students of Islamic Azad University.

Table 7 shows that the chi-square value for cultural capital variable was 15.004 and for economic capital was 28.028, both with the degree of freedom of 4. As the significance values calculated for both cultural capital and economic capital variables are less than 0.05 (P < 0.5), it can be said that there is a significant difference between cultural capital and economic capital of the students.

In order to examine the differences in social capital among students from different universities, one-way analysis of variance (ANOVA) was used. As Table 8 shows, the size of the F-value was 0.492 with the degree of freedom of 4, significance value of which was 0.742. As the significance level is larger than 0.05, it can be said that with regard to social capital, there is no statistically significant difference among major academic discipline groups students.

Hypothesis 3: In order to investigate the difference between students in public and private universities regarding their cultural and economic capital, the Mann-Whitney U test was used. As it is shown in Table 9, the mean rank of public university students in cultural capital was 178.84 and the mean rank of private university students regarding cultural capital was 212.19. In addition, the mean rank of the students in public universities regarding social capital was 176.64, and the mean rank in cultural   capital   for  private  university  students  was 218.07.

As Table 10 shows, regarding the cultural capital variable, the values ​​obtained for the Mann-Whitney U, Wilcoxon and Z-value are 14183, 42386 and -2.875, respectively. Moreover, regarding the economic capital variable, the values obtained for the Mann-Whitney U, Wilcoxon and Z value are 13660, 41836 and -3.632, respectively. As the significance values for both cultural capital and economic capital variables are less than 0.05 (P < 0.05), it can be said that the null hypothesis is rejected, and that there is a significant difference in the cultural capital and economic between public and private university students.

In order to investigate the differences in social capital between public and private university students, t-test was used. As shown in Table 11, the average score of students in private universities in social capital was 63.6486 and the standard deviation was 12.52 and the average score of students in state universities in social capital was 64.7972 and the standard deviation was 14.30. The t-test results are shown in Table 12. As shown

in the table, the t-value is calculated as -0.809, with the degree of freedom as 363, and significance level as 0.217. As the significance level is more than 0.05 (P > 0.05), the null hypothesis can be accepted for the social capital variable, and it can be said that there is no significant difference in social capital between private and public university students.

Hypothesis 4: In order to investigate the difference between the cultural and economic capital of tuition-based and tuition-free education, the Mann-Whitney U test was used. As shown in Table 13, the mean rank of the cultural capital of tuition-based universities’ students was 202.97 and the mean rank of tuition-free universities’ students regarding cultural capital was 172.32. Moreover, the mean rank in social capital of tuition-based universities’ students was 206.60 and the mean rank of tuition-free universities’ students in social capital was 168.73.

According to Table 14 regarding the cultural capital variable, values ​​obtained for Mann-Whitney U, Wilcoxon and Z-value were 14346, 24642 and -2.636, respectively. In addition, regarding the economic capital variable, the values obtained for Mann-Whitney U, Wilcoxon and Z-value were 13832.5, 24128.5 and -3.301, respectively. Since the significance value obtained for cultural capital value is larger than 0.05 (p > 0.05), the null hypothesis can be accepted and it can be said that there is no significant difference between tuition-based and tuition-free universities’ students regarding cultural capital. Also, since the significant value obtained for the economic capital variable is less than 0.05 (P < 0.05), the study can reject the null hypothesis; thus, there is a significant difference between tuition-based and tuition-free universities’ students regarding their economic capital.

In order to investigate the difference in social capital between tuition-based and tuition-free universities’ students, independent t-test was used. As it can be seen in Table 15, the average score of tuition-exacting universities’ students regarding social capital was  64.008 and the standard deviation was 13.63, and the average social capital score of tuition-free universities’ students was 64.2446 and the standard deviation was 12.61. T-test results are shown in Table 16. As shown in the table, the t-value is -0.165, with the degree of freedom as 363, and significance level as 0.609. As the significant level obtained is larger than 0.05 (P > 0.05), the null hypothesis is accepted; thus, it can be said that there is no significant difference between tuition-based and tuition-free universities’ students regarding their social capital.

Justice and equity are human social needs that manifest in the relations between the government and the people, customs and social conventions, laws and programs as well as in people’s ways of dealings with one another. The educational system is the most appropriate institution for countering the inequalities in small or large scales in every country. And fair distribution of educational resources and opportunities to materialize sustainable educational development and enjoyment of all people of good-quality education is one of the duties of educational planners (Sameri, 2013).

However, although formal education, especially higher education, plays an important role in social mobility, it should not be expected that its policies aim only at creating justice and equal opportunities in education. Rather, the study must focus his attention on and have a systematic view toward other influential factors in the process, such as employment policy, cultural, social and economic policy and financial needs (Dehnavi, 2003). However in higher educational system in Iran due to the policies of development of higher education and creating equal opportunities for all to access higher education, the polices of student selection has been changed and different quotas for deprived areas has been assigned; it seems despite of government's developmental policies; factors such as enjoyment of affluent families from qualitative school training, shadow educations, cultural capital, economic capital, and social capital of students has created stratified structure in higher education, and has strengthened the class structure of society. Thus, this study attempted to examine the issue of higher education class stratification through evaluating status of students in different academic majors in terms of cultural, social and economic capital elements.

The results of the  first hypothesis  concerning  whether there is a difference in cultural capital and economic capital indicate that medical students’ group holds the highest rank compared to other groups. The engineering students hold the second and humanities students rank the third. While the agriculture students, medicine-related sciences, and basic sciences are the next in order. As these results indicate, the first hypothesis is confirmed. These findings are consistent with Noghani (2010), Janalizadeh et al. (2011), Garoon (2003, 2006), Isa zadeh (2008), Khodaei (2008), Noorbakhsh (2010) and Jalali (2010), which confirm the positive influence of economic and cultural capital of the family on being admitted to universities and getting access to educational opportunities. In addition, the results are in line with Noghani’s (2010) results that family’s social capital has no significant effect on students’ likelihood to passing the University Admission Exam. However, contrary to the finding of Ghianpoor et al. (2013), which found that sociology   students   are superior to medical students regarding cultural capital.

The results of examining the differences in cultural capital and economic capital in terms of the type of university showed that Azad University students have the highest and State University students have the lowest ranking regarding cultural capital. The students of University of Medical Sciences, Non-profit and Payam-e-Noor rank the second, third and fourth regarding cultural capital. Furthermore, Azad University students also have the highest and State University students hold the lowest rank regarding economic capital. Students of University of Medical Sciences, Payam-e-Noor, and Non-profit rank the second, third and fourth, respectively, regarding the economic capital.

Examining whether there is a difference between public and private and tuition-based and tuition-free universities’ students regarding cultural and economic capital revealed that the mean rank of private universities’ students is higher than mean rank of state universities’ students. Furthermore, the mean rank of tuition-based universities’ students in cultural and economic capital was higher than tuition-free universities’ students. The results confirm the second hypothesis and are consistent with Esmaeili (2013). Thus, it can be concluded that the privatization of higher education has had consequences like increasing social inequalities, which has resulted in class stratification of education, inequalities in access to educational opportunities, success of opportunistic incentives of the private sector, and inflicting change in favor of the higher classes of society.

The earlier findings indicate that students admitted to Islamic Azad, Payam-e-Noor and Non-profit Universities enjoy a higher cultural and economic capital in comparison with State University students. These students after graduating and in order to entering work market, act better than lower class students in competitive field of employment and earn more success. As such, the higher educational system reinforces the class structure of society and it can be concluded that the type of university has played an important role in stratification. As Shavit and Blossfeld (1993) showed that in most cases, educational expansion did not decrease inequality between social strata. As educational systems expanded, more privileged groups were better positioned to take advantage of new opportunities. Thus, while educational opportunities increased for all groups, the difference between the top and bottom of the social hierarchy persisted (Josipa, 2007).

It should be noted that the findings of this study indicate that there is a class structure among students of humanities, engineering, agriculture, basic sciences, and medical and medical-related sciences in such a way that a significant difference was observed in cultural and economic capital, but no significant difference was found in their social capital. Moreover, the results suggest a class stratification structure exists between students in terms of the university they attend to (State, Azad, Payam-e-Noor, Medical and Non-profit), the type of university (public / private) and university’s tuition status (tuition-based / tuition-free). Thus, the findings confirm stratification of higher education in different aspects. These findings are generally in line with the theoretical research and the results of other studies in the area of educational inequality. As a result, it can be admitted that the higher educational system in Iran is moving toward strengthening the class structure of society and playing such a role is perpetuating the class structure.

The authors have not declared any conflicts of interest.