How emotional intelligence affects inter-organizational relationships in megaprojects: the boundary spanning perspective
DOI: https://doi.org/10.3846/jcem.2025.24102Abstract
Boundary Spanners (BSs) substantially impact relationship development in megaprojects. Yet, previous research only focused on the emotional intelligence (EI) of single-level BSs, e.g., megaproject managers and decision-makers. By clustering BSs into higher-level BSs (HBSs) and middle-lower-level BSs (M&LBSs), this article aims to investigate how to enhance inter-organizational relationships through different-level BSs’ EI and boundary-spanning behaviors including ambassadors, coordination and information scanning behaviors. Data from 119 HBSs and 171 M&LBSs in 15 megaprojects were first collected with a questionnaire survey. 18 semi-structured interviews were then undertaken to give a deeper explanation to the underlying mechanism. The results show that HBSs’ EI is directly and positively associated with inter-organizational relationships. However, the benefit of M&LBSs’ EI in megaprojects can only be realized through the mediating effect of their boundary-spanning behaviors. HBSs’ EI is effective in improving external ambassadors’ activities. In contrast, M&LBSs’ EI is effective in improving information scanning. This study advanced EI and relationship study in megaprojects, stating the mechanism between these two variables varies for different-level boundary spanners.
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boundary spanner, boundary spanning behavior, emotional intelligence, inter-organizational relationships, mixed-method, megaprojectHow to Cite
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References
Ancona, D. G., & Caldwell, D. F. (1992). Bridging the boundary: External activity and performance in organizational teams. Administrative Science Quarterly, 37(4), 634–665. https://doi.org/10.2307/2393475
Ashkanasy, N. M., & Dorris, A. D. (2017). Emotions in the workplace. Annual Review of Organizational Psychology and Organizational Behavior, 4(1), 67–90. https://doi.org/10.1146/annurev-orgpsych-032516-113231
Bar-On, R. (2006). The Bar-On model of emotional-social intelligence (ESI). Psicothema, 18, 13–25.
Barney, J., & Felin, T. (2013). What are microfoundations?. The Academy of Management Perspectives, 27(2), 138–155. https://doi.org/10.5465/amp.2012.0107
Butler, C. J., & Chinowsky, P. S. (2006). Emotional intelligence and leadership behavior in construction executives. Journal of Management in Engineering, 22(3), 119–125. https://doi.org/10.1061/(ASCE)0742-597X(2006)22:3(119)
Cao, T., Locatelli, G., Smith, N., & Zhang, L. (2021). A shared leadership framework based on boundary spanners in megaprojects. International Journal of Managing Projects in Business, 14(5), 1065–1092. https://doi.org/10.1108/IJMPB-03-2020-0090
Carmeli, A., Levi, A., & Peccei, R. (2021). Resilience and creative problem-solving capacities in project teams: A relational view. International Journal of Project Management, 39(5), 546–556. https://doi.org/10.1016/j.ijproman.2021.03.007
Cheung, G. W., & Lau, R. S. (2008). Testing mediation and suppression effects of latent variables: Bootstrapping with structural equation models. Organizational Research Methods, 11(2), 296–325. https://doi.org/10.1177/1094428107300343
Costa, F., Granja, A. D., Fregola, A., Picchi, F., & Staudacher, A. P. (2019). Understanding relative importance of barriers to improving the customer–supplier relationship within construction supply chains using DEMATEL technique. Journal of Management in Engineering, 35(3), Article 04019002. https://doi.org/10.1061/(ASCE)ME.1943-5479.0000680
Creswell, J. W. (2009). Research design: Qualitative, quantitative, and mixed methods approaches (3rd ed). Sage Publications.
Dasu, T., & Johnson, T. (2003). Exploratory data mining and data cleaning. John Wiley & Sons. https://doi.org/10.1002/0471448354
Denicol, J., Davies, A., & Pryke, S. (2021). The organisational architecture of megaprojects. International Journal of Project Management, 39(4), 339–350. https://doi.org/10.1016/j.ijproman.2021.02.002
Di Marco, M. K., Alin, P., & Taylor, J. E. (2012). Exploring negotiation through boundary objects in global design project networks. Project Management Journal, 43(3), 24–39. https://doi.org/10.1002/pmj.21273
Dionne, S. D., Sayama, H., Hao, C., & Bush, B. J. (2010). The role of leadership in shared mental model convergence and team performance improvement: An agent-based computational model. The Leadership Quarterly, 21(6), 1035–1049. https://doi.org/10.1016/j.leaqua.2010.10.007
Droge, C., Claycomb, C., & Germain, R. (2003). Does knowledge mediate the effect of context on performance? Some initial evidence. Decision Sciences, 34(3), 541–568. https://doi.org/10.1111/j.1540-5414.2003.02324.x
Du, W., & Pan, S. L. (2013). Boundary spanning by design: Toward aligning boundary-spanning capacity and strategy in IT outsourcing. IEEE Transactions on Engineering Management, 60(1), 59–76. https://doi.org/10.1109/TEM.2012.2206114
Ertürk, A., & Albayrak, T. (2019). Empowerment and organizational identification: The mediating role of leader–member exchange and the moderating role of leader trustworthiness. Personnel Review, 49(2), 571–596. https://doi.org/10.1108/PR-02-2018-0054
Etikan, I. (2016). Comparison of convenience sampling and purposive sampling. American Journal of Theoretical and Applied Statistics, 5(1), 1–4. https://doi.org/10.11648/j.ajtas.20160501.11
Fallon, C. K., Panganiban, A. R., Wohleber, R., Matthews, G., Kustubayeva, A. M., & Roberts, R. (2014). Emotional intelligence, cognitive ability and information search in tactical decision-making. Personality and Individual Differences, 65, 24–29. https://doi.org/10.1016/j.paid.2014.01.029
Fellows, R., & Liu, A. M. M. (2012). Managing organizational interfaces in engineering construction projects: Addressing fragmentation and boundary issues across multiple interfaces. Construction Management and Economics, 30(8), 653–671. https://doi.org/10.1080/01446193.2012.668199
Fireman, M. C. T., Saurin, T. A., Formoso, C. T., Koskela, L., & Tommelein, I. D. (2023). Slack in production planning and control: A study in the construction industry. Construction Management and Economics, 41(3), 256–276. https://doi.org/10.1080/01446193.2022.2135749
Fornell, C., & Larcker, D. F. (1981). Evaluating structural equation models with unobservable variables and measurement error. Journal of Marketing Research, 18(3), 375–381. https://doi.org/10.1177/002224378101800312
Ghuman, U. (2011). Building a model of group emotional intelligence. Team Performance Management: An International Journal, 17(7/8), 418–439. https://doi.org/10.1108/13527591111182661
Gittell, J. H. (2002). Coordinating mechanisms in care provider groups: Relational coordination as a mediator and input uncertainty as a moderator of performance effects. Management Science, 48(11), 1408–1426. https://doi.org/10.1287/mnsc.48.11.1408.268
Goleman, D. (1995). Emotional intelligence. Bantam Books.
Goleman, D. (2006). Emotional intelligence. Bantam Books.
Guo, W., Lu, W., Hao, L., & Gao, X. (2023). Interdependence and information exchange between conflicting parties: The role of interorganizational trust. IEEE Transactions on Engineering Management, 70(1), 156–172. https://doi.org/10.1109/TEM.2020.3047499
Gupta, P., & Jha, K. N. (2023). A decentralized and automated contracting system using a blockchain-enabled network of stakeholders in construction megaprojects. Journal of Management in Engineering, 39(4), Article 04023021. https://doi.org/10.1061/JMENEA.MEENG-5366
Helfat, C. E., & Winter, S. G. (2011). Untangling dynamic and operational capabilities: Strategy for the (n)ever-changing world. Strategic Management Journal, 32(11), 1243–1250. https://doi.org/10.1002/smj.955
Hetemi, E., Gemünden, H. G., & Meré, J. O. (2020). Embeddedness and actors’ behaviors in large-scale project life cycle: Lessons learned from a high-speed rail project in Spain. Journal of Management in Engineering, 36(6), Article 05020014. https://doi.org/10.1061/(ASCE)ME.1943-5479.0000849
Hopkins, M. M., & Yonker, R. D. (2015). Managing conflict with emotional intelligence: Abilities that make a difference. Journal of Management Development, 34(2), 226–244. https://doi.org/10.1108/JMD-04-2013-0051
Huang, Y., Luo, Y., Liu, Y., & Yang, Q. (2016). Interorganizational exchanges in emerging markets: A boundary-spanning perspective. Journal of Management, 42(6), 1557–1587. https://doi.org/10.1177/0149206313511115
Jelodar, M. B., Yiu, T. W., & Wilkinson, S. (2016a). A conceptualisation of relationship quality in construction procurement. International Journal of Project Management, 34(6), 997–1011. https://doi.org/10.1016/j.ijproman.2016.03.005
Jelodar, M. B., Yiu, T. W., & Wilkinson, S. (2016b). Relationship-quality judgment model for construction project procurement: A conjoint measurement. Journal of Construction Engineering and Management, 142(7), Article 04016012. https://doi.org/10.1061/(ASCE)CO.1943-7862.0001104
Jiang, J., Klein, G., & Müller, R. (2022). Mixed-methods research for Project Management Journal®. Project Management Journal, 53(3), 215–218. https://doi.org/10.1177/87569728221088107
Jordan, P. J., & Troth, A. C. (2002). Emotional intelligence and conflict resolution: Implications for human resource development. Advances in Developing Human Resources, 4(1), 62–79. https://doi.org/10.1177/1523422302004001005
Joseph, D. L., & Newman, D. A. (2010). Emotional intelligence: An integrative meta-analysis and cascading model. Journal of Applied Psychology, 95(1), 54–78. https://doi.org/10.1037/a0017286
Joseph, D. L., Jin, J., Newman, D. A., & O’Boyle, E. H. (2014). Why does self-reported emotional intelligence predict job performance? A meta-analytic investigation of mixed EI. Journal of Applied Psychology, 100(2), 298–342. https://doi.org/10.1037/a0037681
Joshi, A., Pandey, N., & Han, G. H. (2009). Bracketing team boundary spanning: An examination of task-based, team-level, and contextual antecedents. Journal of Organizational Behavior, 30(6), 731–759. https://doi.org/10.1002/job.567
Khosravi, P., Rezvani, A., & Ashkanasy, N. M. (2020). Emotional intelligence: A preventive strategy to manage destructive influence of conflict in large scale projects. International Journal of Project Management, 38(1), 36–46. https://doi.org/10.1016/j.ijproman.2019.11.001
Klein, G., & Müller, R. (2019). Quantitative research submissions to Project Management Journal®. Project Management Journal, 50(3), 263–265. https://doi.org/10.1177/8756972819840141
Laborde, S., Lautenbach, F., Allen, M. S., Herbert, C., & Achtzehn, S. (2014). The role of trait emotional intelligence in emotion regulation and performance under pressure. Personality and Individual Differences, 57, 43–47. https://doi.org/10.1016/j.paid.2013.09.013
Lawler, E. J. (2001). An affect theory of social exchange. American Journal of Sociology, 107(2), 321–352. https://doi.org/10.1086/324071
Le, M.-H., Lu, W.-M., & Kweh, Q. L. (2023). The moderating effects of power distance on corporate social responsibility and multinational enterprises performance. Review of Managerial Science, 17(7), 2503–2533. https://doi.org/10.1007/s11846-022-00591-z
Leung, M.-Y., Ahmed, K., & Chan, I. Y. S. (2024). Impact of stressors/stress on organizational commitment of engineers in the construction industry. Buildings, 14(4), Article 956. https://doi.org/10.3390/buildings14040956
Levina, N., & Vaast, E. (2005). The emergence of boundary spanning competence in practice: Implications for implementation and use of information systems. MIS Quarterly: Management Information Systems, 29(2), 335–363. https://doi.org/10.2307/25148682
Li, Y., Lu, Y., Cui, Q., & Han, Y. (2019). Organizational behavior in megaprojects: Integrative review and directions for future research. Journal of Management in Engineering, 35(4), Article 04019009. https://doi.org/10.1061/(ASCE)ME.1943-5479.0000691
Lim, B. T. H., & Loosemore, M. (2017). The effect of inter-organizational justice perceptions on organizational citizenship behaviors in construction projects. International Journal of Project Management, 35(2), 95–106. https://doi.org/10.1016/j.ijproman.2016.10.016
Lindebaum, D., & Jordan, P. J. (2012). Relevant but exaggerated: The effects of emotional intelligence on project manager performance in construction. Construction Management and Economics, 30(7), 575–583. https://doi.org/10.1080/01446193.2011.593184
Löwstedt, M., Räisänen, C., & Leiringer, R. (2018). Doing strategy in project-based organizations: Actors and patterns of action. International Journal of Project Management, 36(6), 889–898. https://doi.org/10.1016/j.ijproman.2018.05.002
Lu, S., & Hao, G. (2013). The influence of owner power in fostering contractor cooperation: Evidence from China. International Journal of Project Management, 31(4), 522–531. https://doi.org/10.1016/j.ijproman.2012.10.008
Maqbool, R., Sudong, Y., Manzoor, N., & Rashid, Y. (2017). The impact of emotional intelligence, project managers’ competencies, and transformational leadership on project success: An empirical perspective. Project Management Journal, 48(3), 58–75. https://doi.org/10.1177/875697281704800304
Marrone, J. A. (2010). Team boundary spanning: A multilevel review of past research and proposals for the future. Journal of Management, 36(4), 911–940. https://doi.org/10.1177/0149206309353945
Mayer, J. D., Salovey, P., Caruso, D. R., & Sitarenios G. (2001). Emotional intelligence as a standard intelligence. Emotion, 1(3), 232–242. https://doi.org/10.1037/1528-3542.1.3.232
Mayer, J. D., Caruso, D. R., & Salovey, P. (2016). The ability model of emotional intelligence: Principles and updates. Emotion Review, 8(4), 290–300. https://doi.org/10.1177/1754073916639667
Mazur, A., Pisarski, A., Chang, A., & Ashkanasy, N. M. (2014). Rating defence major project success: The role of personal attributes and stakeholder relationships. International Journal of Project Management, 32(6), 944–957. https://doi.org/10.1016/j.ijproman.2013.10.018
Merlin, J. I., & Prabakar, S. (2024). Trends and patterns: A bibliometric analysis of emotional intelligence and its implications for strategic leadership. Multidisciplinary Reviews, 7(4), Article 2024063. https://doi.org/10.31893/multirev.2024063
Mihalache, O. R., Jansen, J. J. P., Van Den Bosch, F. A. J., & Volberda, H. W. (2014). Top management team shared leadership and organizational ambidexterity: A moderated mediation framework. Strategic Entrepreneurship Journal, 8(2), 128–148. https://doi.org/10.1002/sej.1168
Nowak, R. (2021). Structural empowerment and serving culture as determinants of organizational identification and turnover intention. Management Research Review, 44(2), 318–340. https://doi.org/10.1108/MRR-02-2020-0064
O’boyle Jr., E. H., Humphrey, R. H., Pollack, J. M., Hawver, T. H., & Story, P. A. (2011). The relation between emotional intelligence and job performance: A meta-analysis. Jounal of Organizational Behavior, 32, 788–818. https://doi.org/10.1002/job.714
Ormiston, M. E., Wong, E. M., & Ha, J. (2022). The role of CEO emotional stability and team heterogeneity in shaping the top management team affective tone and firm performance relationship. The Leadership Quarterly, 33(3), Article 101543. https://doi.org/10.1016/j.leaqua.2021.101543
Palmatier, R. W., Dant, R. P., Grewal, D., & Evans, K. R. (2006). Factors influencing the effectiveness of relationship marketing: A meta-analysis. American Marketing Association, 70, 136–153. https://doi.org/10.1509/jmkg.70.4.136
Patanakul, P., & Shenhar, A. J. (2012). What project strategy really is: The fundamental building block in strategic project management. Project Management Journal, 43(1), 4–20. https://doi.org/10.1002/pmj.20282
Petrides, K. V., & Furnham, A. (2001). Trait emotional intelligence: Psychometric investigation with reference to established trait taxonomies. European Journal of Personality, 15(6), 425–448. https://doi.org/10.1002/per.416
Pitelis, C. N., & Wagner, J. D. (2019). Strategic shared leadership and organizational dynamic capabilities. The Leadership Quarterly, 30(2), 233–242. https://doi.org/10.1016/j.leaqua.2018.08.002
Podsakoff, P. M., MacKenzie, S. B., Lee, J.-Y., & Podsakoff, N. P. (2003). Common method biases in behavioral research: A critical review of the literature and recommended remedies. Journal of Applied Psychology, 88(5), 879–903. https://doi.org/10.1037/0021-9010.88.5.879
Poleacovschi, C., & Javernick-Will, A. (2016). Spanning information and knowledge across subgroups and its effects on individual performance. Journal of Management in Engineering, 32(4), Article 04016006. https://doi.org/10.1061/(ASCE)ME.1943-5479.0000423
Poppo, L., Zhou, K. Z., & Li, J. J. (2016). When can you trust “trust”? Calculative trust, relational trust, and supplier performance.Strategic Management Journal, 37(4), 724–741. https://doi.org/10.1002/smj.2374
Rezvani, A., Chang, A., Wiewiora, A., Ashkanasy, N. M., Jordan, P. J., & Zolin, R. (2016). Manager emotional intelligence and project success: The mediating role of job satisfaction and trust. International Journal of Project Management, 34(7), 1112–1122. https://doi.org/10.1016/j.ijproman.2016.05.012
Rezvani, A., Khosravi, P., & Ashkanasy, N. M. (2018). Examining the interdependencies among emotional intelligence, trust, and performance in infrastructure projects: A multilevel study. International Journal of Project Management, 36(8), 1034–1046. https://doi.org/10.1016/j.ijproman.2018.08.002
Rezvani, A., Ashkanasy, N., & Khosravi, P. (2020). Key Attitudes: unlocking the relationships between emotional intelligence and performance in construction projects. Journal of Construction Engineering and Management, 146(4), Article 04020025. https://doi.org/10.1061/(ASCE)CO.1943-7862.0001803
Saad, D. A., & Hegazy, T. (2015). Behavioral economic concepts for funding infrastructure rehabilitation. Journal of Management in Engineering, 31(5), Article 04014089. https://doi.org/10.1061/(ASCE)ME.1943-5479.0000332
Schotter, A. P. J., Mudambi, R., Doz, Y. L., & Gaur, A. (2017). Boundary spanning in global organizations: Boundary spanning in global organizations. Journal of Management Studies, 54(4), 403–421. https://doi.org/10.1111/joms.12256
Schutte, N. S., Malouff, J. M., Hall, L. E., Haggerty, D. J., Cooper, J. T., Golden, C. J., & Dornheim, L. (1998). Development and validation of a measure of emotional intelligence. Personality and Individual Differences, 25(2), 167–177. https://doi.org/10.1016/S0191-8869(98)00001-4
Shi, Q., Chen, X., Xiao, C., & Han, Y. (2022). Network perspective in megaproject management: A systematic review. Journal of Construction Engineering and Management, 148(7), Article 03122002. https://doi.org/10.1061/(ASCE)CO.1943-7862.0002304
Senescu, R. R., Aranda-Mena, G., & Haymaker, J. R. (2013). Relationships between project complexity and communication. Journal of Management in Engineering, 29(2), 183–197. https://doi.org/10.1061/(ASCE)ME.1943-5479.0000121
Shafi, M. Q., Iqbal, R., Shahzad, K., & Unterhitzenberger, C. (2021). The mediating role of project citizenship behavior in the relationship between organizational justice dimensions and project success. Project Management Journal, 52(6), 547–562. https://doi.org/10.1177/87569728211026423
Sözbilir, F. (2023). The impact of emotional intelligence and organizational identification on creativity performance. International Journal of Organizational Leadership, 12(3), 254–268. https://doi.org/10.33844/ijol.2023.60367
Srivastava, R., & Tang, T. L.-P. (2015). Coping intelligence: Coping strategies and organizational commitment among boundary spanning employees. Journal of Business Ethics, 130(3), 525–542. https://doi.org/10.1007/s10551-014-2234-4
Sukanthan Rajendra, D., Hon, C. K. H., Manley, K., Lamari, F., & Skitmore, M. (2022). Key dimensions of the technical readiness of small construction businesses that determine their intention to use ICTs. Journal of Management in Engineering, 38(6), Article 04022055. https://doi.org/10.1061/(ASCE)ME.1943-5479.0001078
Talebi, S., Koskela, L., Tzortzopoulos, P., Kagioglou, M., Rausch, C., Elghaish, F., & Poshdar, M. (2021). Causes of defects associated with tolerances in construction: A case study. Journal of Management in Engineering, 37(4), Article 05021005. https://doi.org/10.1061/(ASCE)ME.1943-5479.0000914
Tezel, A., Koskela, L., & Aziz, Z. (2018). Current condition and future directions for lean construction in highways projects: A small and medium-sized enterprises (SMEs) perspective. International Journal of Project Management, 36(2), 267–286. https://doi.org/10.1016/j.ijproman.2017.10.004
Tushman, M. L., & Scanlan, T. J. (1981). Boundary spanning individuals: Their role in information transfer and their antecedents. Academy of Management Journal, 24(2), 289–305. https://doi.org/10.2307/255842
van Meerkerk, I., & Edelenbos, J. (2018). Facilitating conditions for boundary-spanning behaviour in governance networks. Public Management Review, 20(4), 503–524. https://doi.org/10.1080/14719037.2017.1302248
Wang, G., Locatelli, G., Wan, J., Li, Y., & Le, Y. (2021). Governing behavioral integration of top management team in megaprojects: A social capital perspective. International Journal of Project Management, 39(4), 365–376. https://doi.org/10.1016/j.ijproman.2020.11.005
Wang, L., Jiang, M., Zhu, F., & Song, P. (2022). Untangling employee well-being in projects: A configural analysis of job stressors and psychological needs. Journal of Management in Engineering, 38(4), Article 04022026. https://doi.org/10.1061/(ASCE)ME.1943-5479.0001048
Witz, P., Stingl, V., Wied, M., & Oehmen, J. (2021). Asymmetric legitimacy perception across megaproject stakeholders: The case of the Fehmarnbelt Fixed Link. International Journal of Project Management, 39(4), 377–393. https://doi.org/10.1016/j.ijproman.2021.01.006
Wu, S., Yu, L., Cao, T., Yuan, C., & Du, Y. (2023). How dependence asymmetry and explicit contract shape contractor–subcontractor collaboration: A psychological perspective of fairness. Journal of Construction Engineering and Management, 149(11), Article 04023103. https://doi.org/10.1061/JCEMD4.COENG-13225
Yao, Y., Zhang, L., & Sun, H. (2023). Enhancing project managers’ strategy commitment by leader-leader exchange: The role of psychological empowerment and organizational identification. International Journal of Project Management, 41(3), Article 102465. https://doi.org/10.1016/j.ijproman.2023.102465
Zhang, L., Cao, T., & Wang, Y. (2018a). The mediation role of leadership styles in integrated project collaboration: An emotional intelligence perspective. International Journal of Project Management, 36(2), 317–330. https://doi.org/10.1016/j.ijproman.2017.08.014
Zhang, S., Fu, Y., & Kang, F. (2018b). How to foster contractors’ cooperative behavior in the Chinese construction industry: Direct and interaction effects of power and contract. International Journal of Project Management, 36(7), 940–953. https://doi.org/10.1016/j.ijproman.2018.05.004
Zhang, D., Guo, P., & Zhao, J. (2022). The motives system for developing project-based inter-organizational cooperation. International Journal of Project Management, 40(3), 167–180. https://doi.org/10.1016/j.ijproman.2021.11.010
Zhao, N., Fan, D., Chen, Y., & Wu, C. (2023). Impact of innovation organization network on the synergy of cross-organizational technological innovation: Evidence from megaproject practices in China. Journal of Civil Engineering and Management, 29(1), 50–66. https://doi.org/10.3846/jcem.2023.18051
Zheng, X., Lu, Y., Le, Y., Li, Y., & Fang, J. (2017). Formation of interorganizational relational behavior in megaprojects: Perspective of the extended theory of planned behavior. Journal of Management in Engineering, 34(1), Article 04017052. https://doi.org/10.1061/(ASCE)ME.1943-5479.0000560
Zhu, F., Wang, X., Wang, L., & Yu, M. (2021). Project manager’s emotional intelligence and project performance: The mediating role of project commitment. International Journal of Project Management, 39(7), 788–798. https://doi.org/10.1016/j.ijproman.2021.08.002
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