آیا اشغال نقش رهبری و رهبری تحول گرا تاثیرات ژنتیکی و محیطی یکسانی را به اشتراک می گدارند؟

Using data collected from 107 pairs of identical and 89 pairs of fraternal female twins, this study examined the genetic and environmental associations between transformational leadership and leadership role occupancy. Results show that 78% of the covariance between the two leadership variables was attributable to overlapping genetic factors, while 22% of the covariance to overlapping environmental factors. In particular, 13% (2%) of the variance in leadership role occupancy was accounted for by the same genetic (environmental) factors related to transformational leadership. Unique sets of genetic and environmental variables, which are not associated with transformational leadership, explained 16% and 69% of the variance in leadership role occupancy, respectively. The results suggest that multiple manifestations of leadership (i.e., transformational leadership and leadership role occupancy) are differentially heritable. Although the association between these two variables is largely due to overlapping genetic rather than environmental factors, unique (i.e., non-overlapping) genetic and environmental influences still play an important role in impacting these leadership variables.

There is growing evidence that two distinct types of leadership conceptualizations – transformational leadership and leadership role occupancy – are influenced by genetic and environmental factors (Arvey et al., 2006, Arvey et al., 2007, Johnson et al., 1998 and Johnson et al., 2004). Transformational leadership denotes leadership behaviors which transform subordinates beyond their self interests to pursue the good of a group or organization (Bass & Bass, 2008). Leadership role occupancy refers to whether people occupy positions of leadership in organizations (Arvey et al., 2006). A question that remains unanswered, however, is whether the same genetic and/or environmental factors affecting transformational leadership also affect leadership role occupancy? That is, is there a common set of genetic and/or environmental factors that influence the two types of leadership? The existence of an overlapping set of genetic factors on the two leadership variables is often referred to as whether there is a “genetic correlation” between them. Genetic correlation is defined as the degree of overlap between observed variables accounted for by overlapping or identical genetic factors that are independent of the overall genetic influence on the two variables (Kovas & Plomin, 2007, p. 284). Although for some variables genetic factors may have only moderate levels of effects, the genetic correlation between two variables can range from 0.0 to 1.0 (Plomin & Spinath, 2002, p. 169). The same is true for “environmental correlation”, which refers to the overlap between two observed variables attributable to overlapping environmental factors (Kovas & Plomin, 2007). An investigation of the overlapping genetic and environmental factors associated with transformational leadership and leadership role occupancy is of both theoretical and practical significance. First, estimating the magnitude of genetic and environmental correlations can help to explain in greater details why transformational leadership behaviors are positively related to one's obtainment of leadership roles in organizations. One reason for a positive relationship between these two leadership constructs is that people exhibiting transformational leadership behaviors are likely to have high level of job performance (Judge & Piccolo, 2004). Moreover, people with high level of job performance are likely to be perceived as being competent. As such, they tend to be promoted by their superiors and organizations into leadership roles1 (Hogan, Curphy, & Hogan, 1994). There are two potential underlying mechanisms for such an association. The observed relationship may be mainly due to the person (i.e., the same genes make a person display transformational leadership behaviors and also help them to occupy leadership positions). Or, it could be largely because of environmental/developmental events that simultaneously impact leadership behaviors and the attainment of formal leadership positions (e.g., clan culture emphasizing cooperation, cohesion, and employee development may give rise to both transformational leadership behaviors and leader development, Cameron & Quinn, 1999). By simultaneously examining these two potential mechanisms and comparing their magnitudes of effect, this study has the potential to offer unique insights into leadership research and provide effective guidelines for leadership development practices. Second, exploring the overlapping and unique genetic influence is helpful in understanding the relative locus of influence for a particular variable. If one is looking at one leadership construct, it would be helpful to know if the same genetic structures (i.e., DNAs) affect other leadership variables, or whether the leadership construct is under predominantly unique genetic influences. Modern molecular genetics are beginning to explore specific gene linkages to individual characteristics and behavior such as personality (Ebstein et al., 1996), voting behavior (Fowler & Dawes, 2008), financial decision making (Dreber et al., 2009), and more recently job satisfaction (Song et al., in press). It is also theorized that potential brain functions may mediate these associations (Senior, Lee, & Butler, 2010). Arvey and Bouchard (1994) suggested utilizing this approach to study relationships between specific genes and work-related constructs such as job satisfaction as well as leadership. Indeed, Senior et al. (2009) have reported significant correlations between self-report transformational leadership behaviors and two specific genes. Based on prior research on genetic correlation between diverse types of cognitive abilities (Pedersen et al., 1994 and Petrill, 1997), we expect that if the genetic correlation between transformational leadership and leadership role occupancy is high, then the same genetic structure may influence both types of leadership behaviors. Particularly, if one specific gene or set of genes is identified to be associated with transformational leadership behaviors, it can be expected that the same gene or gene set can also be related to leadership role occupancy (Plomin & Spinath, 2002). The results of prior research on cognitive abilities have been summarized in the “generalist genes” hypotheses, positing that the same genes or gene sets modulate most cognitive abilities and disabilities (Kovas and Plomin, 2006 and Kovas and Plomin, 2007). Consequently, if a high genetic correlation can be found between transformational leadership and leadership role occupancy, then similar “generalist genes” hypotheses can also be formulated in the leadership domain. In addition, investigating the influence of overlapping environmental factors on the two leadership constructs has critical practical implications. Previous studies (e.g., Arvey et al., 2007) show that both family and work experiences significantly contributed to leadership role occupancy. Identifying overlapping and unique environmental factors which can affect transformational leadership and leadership role occupancy can not only shed light on whether critical experiences exist that are important for both of the two leadership constructs, but also has implications on whether the same type of leadership training methods can help one individual behave as a transformational leader and occupy formal roles in the organizational hierarchy. If there are much overlapping environmental influences on the two types of leadership, then we could implement the same training interventions to develop people to become a transformational leader and become a leader. If the overlapping environmental influences do not exist, then different training programs should be utilized. In summary, the objective of the present study is twofold. First, we investigate the “genetic correlation” between transformational leadership and leadership role occupancy, attempting to quantify the extent of overlap between the genetic factors influencing the two leadership variables. Second, we estimate the extent of overlap between the environmental factors associated with the two leadership constructs. In doing so, this study contributes leadership research by providing a deeper understanding why multiple manifestations of leadership are related.

Building on previous studies on leadership and behavioral genetics literature, this study investigated the influence of genetic and environmental factors on two leadership constructs — transformational leadership and leadership role occupancy and examined whether there exists overlapping sets of genetic and/or environmental variables which affect the two leadership constructs simultaneously. The results of behavioral genetic analyses using data collected from identical and fraternal female twins generally supported the notion that transformational leadership and leadership role occupancy are shaped by overlapping genetic and environmental factors. Overlapping genetic factors made a major contribution in the correlation between the two observed leadership variables. Unique genetic and environmental factors also play important roles in influencing the two leadership variables. This study found that 48% variance in transformational leadership (the heritability of leadership role occupancy has been reported in Arvey et al., 2007) was accounted for by additive genetic factors. On the flip side, non-shared environmental factors explained 52% variance in transformational leadership. Transformational leadership appears more heritable than leadership role occupancy (approximately 30%, Arvey et al., 2006 and Arvey et al., 2007) which is consistent with previous results (Johnson et al., 2004 and Johnson et al., 1998). The seeming difference in the two heritability estimates, though not significant (95% confidence intervals overlap) is interesting. It suggests that occupying supervisory positions seems more determined by environmental factors, compared to just displaying transformational leadership behaviors. For instance, although people can display transformational leadership behaviors, they may need to be perceived as leader-like first (e.g., competent and visionary, Hogan et al., 1994) before being promoted into leadership positions by managers/organizations (Lord, Foti, & De Vader, 1984). A further speculation would be that genetic influence on leadership role occupancy may hinge on contextual factors, such as supervisor's sponsorship, organization's HRM practices, and so forth (Zhang, Ilies, & Arvey, 2009). This might be an intriguing avenue for future research. Second, results of the current study show that transformational leadership and leadership role occupancy were genetically correlated (.68). Specifically, overlapping genetics factors contributed 78% of the correlation between the two observed leadership variables; while overlapping environmental factors contributed the remaining 22% of the correlation. Furthermore, the same genetic factors influencing transformational leadership also account for 13% of the variance in leadership role occupancy. On the other hand, leadership role occupancy was also shaped by another set of unique genetic factors, which explained 16% of the variance of this variable. Stated differently, slightly less than 50% (.13 / (.13 + .16)) genetic influence on leadership role occupancy was attributable to the same genetic factors associated with transformational leadership. This finding, if replicated in future studies, has important implications for future leadership research. It reveals that a major part of the correlation between the two observed leadership variables is attributable to overlapping genetic, rather than environmental, factors. Thus when researchers study variables which might simultaneously influence multiple leadership constructs in future studies, they need focus more on the person-related variables (e.g., personality and general mental ability), rather than environmental factors. Further, this finding is also of significance to molecular genetic research on leadership. For instance, if future studies identify specific gene or gene set associated with transformational leadership, there is a good chance that the same gene or gene set may also be related to leadership role occupancy. However, interpretation of this finding should be cautious because although transformational leadership and leadership role occupancy were moderately genetically correlated, slightly more than 50% (.16 / (.13 + .16)) of the variance in leadership role occupancy attributable to genetic factors was driven by a different set of genetic factors which are not shared by transformational leadership. Unique genetic factors overlapped with transformational leadership seem equally important to leadership role occupancy. Lastly, the findings of the current study also suggest that transformational leadership and leadership role occupancy are slightly “environmentally correlated” (.18); non-shared environmental factors which were identical to both variables explained 52% variance in transformational leadership but only little (2%) variance in leadership role occupancy. Interpretation of the small “environmental correlation” between the two leadership construct should consider the relatively large amount of variance (69%) in leadership role occupancy accounted for by unique environmental factors. The results suggest that, although transformational leadership and leadership role occupancy are driven, to certain extent, by the same set of environmental factors, unique environmental factors play a more important, or major, role in influencing leadership role occupancy. Taken together, findings of the current study are consistent with research on diverse types of cognitive abilities, which has shown that it is the “specialist environments” (i.e., unique environmental factors) that distinguishes between different cognitive abilities, albeit “generalist genes” account for their commonalities (Kovas and Plomin, 2006 and Kovas and Plomin, 2007). The findings have implication to leadership development and training. On the one hand, the same set of experience (e.g., work experience) may be useful for development of transformational leadership but not very useful for individuals in becoming a leader. On the other hand, one set of leadership development and training programs may help individuals to occupy a supervisory position, but they may not be very successful in developing transformational leadership. This study is limited in identifying any specific overlapping sets of genetic factors (e.g., particular DNA polymorphisms) and environmental factors which affect both transformational leadership and leadership role occupancy. Molecular genetic studies are making progress in the search for specific genetic polymorphisms for certain phenotypic (measured or observed) variables. For instance, researchers have identified particular genetic polymorphism related to attachment styles (Gillath, Shaver, Baek, & Chun, 2008), rule breaking (Burt, 2009), creativity (Keri, 2009), and more recently job satisfaction (Song et al., in press). Locating particular set of DNA polymorphism (e.g., Dopamine genes) for leadership would be an interesting avenue for future research (Senior et al., 2009). Likewise, searching for specific environmental factors, which give rise to leadership role occupancy, but not transformational leadership, is another interesting route for future studies. As an example, Avolio, Rotundo, and Walumbwa (2009) reported that rule breaking behaviors and parenting styles played an important role in influencing leadership role occupancy. Another limitation has to do with the use of female twins. Although previous research has not found gender difference in the magnitudes of genetic influence on leadership role occupancy (Arvey et al., 2006 and Arvey et al., 2007) and on transformational leadership (Johnson et al., 2004), respectively, one could not automatically assume that the magnitude of genetic correlations are the same across gender groups. Future studies could employ samples with balanced gender groups to test the generalizability of this study to males. In addition, the particular age range of the sample (48–68) may also limit the generalizability of our results. Research on gender gap in managerial jobs has shown that during the time period from 1970s to 1980s, approximately the early career development stage of the study sample, women's under-presentation in managerial occupations was more serious than nowadays (e.g., Powell & Graves, 2003, p. 18).3 Moreover, compared to their man counterparts, women occupy less high rank managerial positions (Catalyst, 1996) and get promoted at a slower pace (e.g., Stroh, Brett, & Reilly, 1992). One reason for such gender gap is that people seem to hold stereotypical belief that effective managers usually possess masculine traits (such as being dominant, aggressive, etc.), rather than feminine traits (Powell, Butterfield, & Parent, 2002). Future studies may examine how societal changes influence heritability of leadership role occupancy for females. On a related matter, heritability estimates have been found to vary with age, which may also pose another limitation to the findings of this study. For instance, previous behavioral genetic research has shown that genetic influence on general mental ability increases from childhood to adulthood (Plomin et al., 2008). Future studies may probe whether age moderates genetic influence on leadership constructs. As previous behavioral genetics research on transformational leadership (Johnson et al., 2004 and Johnson et al., 1998), our study is also limited in using the self-report measure of transformational leadership primarily due to pragmatic reasons. Although we provided empirical evidence for its criterion related validity by showing its correlations with core self-evaluations, social potency, achievement, social closeness, and personal income, it is generally viewed that self report measure of leadership behaviors is less valid and reliable than other ratings. It would be useful to replicate and extent the current study using other report measures of transformational leadership in future studies. We only studied two types of leadership constructs in the current study. It would be fruitful for future studies to examine heredity and environmental influences on other aspects of leadership, such as leader member exchange, supportive leadership, initiating structure and consideration, empowering leadership, ethical leadership, and so forth. In conclusion, our findings show that both transformational leadership and leadership role occupancy are heritable, with transformational leadership has a relatively larger heritability than role occupancy. Moreover, about less than half of the variance of role occupancy explainable by genetic factors can be attributed to the same overlapping set of genetic factors that underpin the heritability of transformational leadership. Future studies can explore specific genes which can be associated with both leadership role occupancy and transformational leadership.