بررسی اثرات تجانس و کدهای شخصیتی هلند در رضایت شغلی : استفاده از تکنیک های مدل سازی سلسله مراتبی خطی

This study applied hierarchical linear modeling to investigate the effect of congruence on intrinsic and extrinsic aspects of job satisfaction. Particular focus was given to differences in job satisfaction by gender and by Holland’s first-letter codes. The study sample included nationally represented 1462 female and 1280 male college graduates who held full-time jobs in 2000. Congruence was measured by using actual occupational and academic major codes. After controlling for the differences across three-letter Holland personality codes, results indicate that job satisfaction was largely a function of individual attributes rather than disparities in personality types. Holland’s congruence was most effective in explaining intrinsic dimensions of job satisfaction for females, and less effective for extrinsic job satisfaction for both genders. Social females and males were less satisfied with extrinsic satisfaction, while Conventional and Social females were more satisfied with intrinsic features in their vocational environments.

While the importance of job satisfaction is evident in one’s personal life, job satisfaction is a rather complex concept and is measured by various work-related conditions. The classic two-factor classification theorized by Herzberg (Herzberg, 1966 and Herzberg et al., 1959) suggests two types of job satisfaction – intrinsic and extrinsic job satisfaction. Intrinsic satisfaction is related to job content and includes such factors as recognition, work importance, career advancement and personal growth. Extrinsic factors are associated with job context, which includes job security, salary, and fringe benefits. The chief distinction between these two factors is that intrinsic factors serve as motivators that lead to job satisfaction, while extrinsic factors are associated with vocational aspects that cause job dissatisfaction, but do not lead to positive satisfaction. Herzberg’s intrinsic and extrinsic typology has been widely used in studies that address job satisfaction (Smart et al., 1986, Volkwein and Zhou, 2003 and Wolniak and Pascarella, 2005). In the earlier study by Smart et al. (1986), intrinsic and extrinsic job satisfaction was discussed in relation to the degree of Holland’s congruence between college majors and post-graduate occupations. They found that a higher level of congruence had a significant positive effect on intrinsic job satisfaction for male and female subjects. However, congruence was less associated with extrinsic job satisfaction, particularly for female subjects. Using a causal modeling approach Wolniak and Pascarella (2005) suggested Holland’s congruence was causally related to intrinsic job satisfaction. Other studies addressed job satisfaction using data that were limited to certain occupational fields. For instance, Volkwein and Zhou (2003) investigated job satisfaction among public and private university administrators, and found that intrinsic satisfaction was the most significant impact on overall satisfaction. Certain personal attributes have been incorporated consistently across these studies on job satisfaction in different occupational fields, namely academic majors and gender. The main role of academic majors is to estimate their congruence with occupations and examine the effect of the congruence on job satisfaction (e.g., Smart et al., 1986 and Wolniak and Pascarella, 2005). As for gender, Marini, Fan, Finley, and Beutel (1996) explored gender differences in job values related to intrinsic and extrinsic rewards using longitudinal data of high school seniors. They found that females valued intrinsic rewards more than their male counterparts. Using Holland’s six hexagon codes for work environment, Elton and Smart (1988) reported gender differences in extrinsic factors in job satisfaction. They found that females were more dissatisfied with their income, fringe benefits, and advancement opportunities than males when working in Social environments. Fricko and Beehr (1992) addressed gender differences in job satisfaction, and reported that the link between congruence and job satisfaction was affected by labor market segmentation based on gender. They discovered that females showed a more positive association between congruence and job satisfaction when they had female-concentrated jobs. This phenomenon was also true for males, as the relationship between congruence and job satisfaction was more positive when having male-concentrated jobs. Thus, the link between congruence and job satisfaction is strengthened as the proportion of the same gender workers increases in vocational environments. For example, given that nursing is a female-concentrated field, male nurses less likely to be satisfied with their jobs than female nurses when the level of congruence is held constant for both genders. The findings by Elton and Smart (1988) indicate that the level of job satisfaction vary across Holland hexagonal codes. However, existent research studies have primarily focused on the effect of congruence on job satisfaction, but failed to appropriately control for varying levels of job satisfaction by Holland codes. Thus, it is rather difficult to infer the ‘net’ effect of congruence on job satisfaction. Built on Holland’s vocational theory, the present study explores if job satisfaction is a function of person–environment-fit, such as Holland congruence, or a function of personality characteristics that are unique to Holland hexagonal codes. In addition to uniquely addressing the role of congruence on job satisfaction, the present study differs from previous studies in several important areas. First, instead of using single institutional data (e.g., Fricko & Beehr, 1992), the study employs a national database of college graduates for more generalizable interpretations of study findings. The subjects in the current study were also in the labor force for similar periods, instead of having various lengths of career experiences after college. Furthermore, individual perception was typically used to measure a level of congruence in previous studies (e.g., Smart et al., 1986 and Wolniak and Pascarella, 2005). Holland’s occupational three-letter code is assigned to each reported occupation in the study data. Thus, actual occupational codes and academic majors are used to estimate the level of congruence in this study. Lastly, while single-linear regression equation modeling has been the predominant analytical technique in previous studies, the present study applies a multi-level linear regression technique known as hierarchical linear modeling (HLM) to yield robust estimates of Holland’s congruence on job satisfaction. 1.1. Measures of Holland’s congruence Holland’s six-letter hexagon is the most comprehensive theory to test the person–environment fit in research on career choices, and has been widely used as a theoretical framework to address various outcomes, such as job satisfaction and performance. According to Holland (1997), there are six personality types (Realistic, Investigative, Artistic, Social, Enterprising, and Conventional), in which people can be categorized. He also theorizes that work environments can be categorized by these six types. The focal point of Holland’s theory is that the level of congruence between an individual personality pattern and the pattern of work environments. While researchers agree with the positive effect of high congruence on vocational output, they have suggested numerous indices to estimate the level of congruence. Complexity in these indices greatly varies from matching between first-letter person and environment codes (Holland, 1997) to inclusion of a correlation matrix in weighted estimates, such as K–P index by Kwak and Pulvino (1982). Given a number of different indices to measure Holland’s congruence, researchers offered studies to examine these indices. In earlier years, Spokane (1985) offered his review of 63 studies on Holland’s congruence to measure outcomes, such as stability and satisfaction. Subsequently Spokane’s study was followed by the meta-analysis by Assouline and Meir (1987). In 1994, Brown and Gore advanced research on Holland’s congruence theory by investigating 11 extent congruence indices and their performance for sensitivity (i.e., how well indices make discriminations between persons and environments). They concluded that congruence indices were not created equally. Then, Brown and Gore (1994) offered the index they developed instead (C Index) to overcome shortcomings found in these 11 indices. Young, Tokar, and Subich (1998) tested 11 congruence indices including the C Index against job satisfaction. They found that there was correlation between indices. However, they suggested that selection of index would not yield substantial impact on measuring job satisfaction. They concluded that Holland’s personality type was more influential to job satisfaction than a level of congruence. As for other outcomes, such as academic achievement, Horn (2004) examined effects of ten indices measuring congruence between personality and academic major types on academic achievement (i.e., GPA) for college students using data from a single institution. He found only Holland’s first-letter agreement to be statistically significant to detect a gender effect. Performance of congruence indices is sensitive to many factors. In recent years, Spokane, Meir, and Catalano (2000) offer a comprehensive review of 66 studies on Holland’s congruence. They suggested that inconclusive findings across correlational studies on congruence were caused by differences in outcome measures, and sampling problems.

Application of the hierarchical linear regression technique allows researchers to estimate variances for individual and Holland Hexagonal code variables separately, which results in producing more robust parameters than using other conventional statistical techniques. Including a diverse set of individual characteristic variables, the present study offers additional empirical findings to the literature. Based on gender differences being found in pervious studies on job satisfaction, this study separated the sample data by gender. Overall, Holland’s first-letter personality codes and congruence index allow researchers to explain variances associated with job satisfaction for females. As pointed out earlier by Young et al. (1998), Holland’s personality type impacted job satisfaction stronger than congruence index in some cases in the current study. For instance, Holland’s Hexagonal Index contributed to larger changes in points than congruence in extrinsic job satisfaction for females. This, however, was not true for intrinsic job satisfaction for females. Congruence measures contributed as much gain as hexagon codes to this particular type of job satisfaction. Additionally, either congruence or Holland’s first-letter codes were not strong predictors for intrinsic job satisfaction among recent male college graduates. Interestingly, Conventional and Social females reported higher intrinsic job satisfaction than Enterprising females. Perhaps, this is a function of the work environment associated with hexagonal codes where Conventional and Social occupations were largely represented by women (Table 2). However, in spite of large proportions represented by males, Investigative and Realistic males did not show significantly higher levels of intrinsic job satisfaction after taking the effect of congruence into account. This implies that the effect of one-gender dominated vocational environments may be gender specific for intrinsic aspects of occupations. Holland’s congruence was most effective in explaining intrinsic job satisfaction among females, which presented a linear relation between congruence and satisfaction. For intrinsic job satisfaction for males, only when males have perfect Holland Hexagonal match between personalities and occupations, does congruence present a positive effect on intrinsic job satisfaction. As for extrinsic job satisfaction, both Social females and males were less satisfied as opposed to their Enterprising counterparts. This supports the earlier findings by Elton and Smart (1988). A puzzling finding related to congruence was statistical significance found in extrinsic job satisfaction for males. Individuals who had 2 points for congruence were less satisfied than those with 1 point. Furthermore, any congruence variables did not yield statistical significance for females. These findings suggest that using congruence to measure extrinsic aspects of occupations is less effective. Such collective findings herein suggest that Holland first-letter codes and congruence are much sensitive to types of job satisfaction and specific genders. Other individual characteristics considered in this study further revealed interesting implications. Annual earnings had positive effects on both types of job satisfaction for male and females subjects. One may suspect that earnings have larger impact on extrinsic job satisfaction, but this was not the case in this study. This may be because a salary is a dissatisfier in that many are never completely content with its amount. Therefore, given the magnitude of the effect being marginal, the monetary incentive is necessity but has a small role in improving job satisfaction. Positive marital experiences were found to improve job satisfaction (Rogers & May, 2003). Even with a lack of the marital quality, the marital status of being married positively influenced both intrinsic and extrinsic job satisfaction in this study. This effect was slightly stronger for males than their counterparts in extrinsic job satisfaction. Higher extrinsic job satisfaction among married men may be reflected by recognizing the importance of fringe benefits, job security and retirement plan in their marriages, which single males may fail to recognize. In the presence of large individual-level variances that are not explained by a set of variables included in the study, further refinement of individual characteristic variables is necessary. In addition, a higher level of certain occupational conditions may not be always associated with enhancing job satisfaction. For example, Realistic workers may prefer a lower level of supervision, while Conventional workers may prefer a highly structured environment. Autonomy would be a source of satisfier or dissatisfier depending on one’s hexagonal code. Therefore, inclusion of autonomy in intrinsic job satisfaction scale leads to spurious interpretation of findings. As pointed out by Smart et al. (2000), “the weak relationship commonly found between congruence and success may be due to conceptual fuzziness and difficulties with measurement associated with assessing educational and occupational success” (p. 178). Perhaps, one example of this “conceptual fuzziness” is that researchers attempt to assess job satisfaction across hexagonal codes, while in fact, it is reasonable to believe that a group of individuals in each hexagonal code may have their own unique set of vocational conditions associated with promoting job satisfaction. Therefore, in conjunction with HLM techniques, further research investigating occupational satisfaction by specific hexagonal code may shed light on the effectiveness of Holland’s congruence.