Purpose – Despite the increasing importance of shared leadership, researches examining its relations with vertical leadership, a complementary source of power, has been scarce. Therefore, the purpose of this paper is to extend the authors’ knowledge on this little-known topic by analysing vertical and shared leadership interactions in a change management project. Design/methodology/approach – A qualitative content analysis based on nine semi-structured interviews with top and middle managers, and a dataset of documents including corporate reports, a Road Map book and presentations was carried out, analysing the reciprocal leadership relationships by using an extended framework, which includes directive, transformational, transactional and empowering behaviours. Findings – Both in radical and incremental step, vertical as well as shared leadership interacted, showing their reciprocal need to deal with change. Leadership approaches and behaviours, conceptually and empirically distinct, even if highly related, are complementary sources that shape a constant compromise, according to the contextual demands of the project, to face change. Research limitations/implications – Further studies could strengthen the generalizability of the findings that suffer for the qualitative method. Moreover further studies could extend leadership interactions beyond leader-change management team relationships to the top-bottom levels of the organization. Contribution to theory is mainly twofold. First, findings highlight that for every specific change phase, both radical and incremental ones, different gradients of vertical and shared leadership are required. Second the authors found that leadership behaviours could be contrasting, requiring the ability to perform the multiple roles and behaviours in a well-balanced way in order to deal with the contextual demands of the change project. Practical implications – The paper includes implication for developing and training leaders, as well as followers, to have effective and multiple leadership skills and be able to apply them in different contexts, both by switching from vertical to shared, and vice versa, and by having the capability to respond with appropriately behaviours to a wide range of situations, that could also be mixed and opposing more than linear. Originality/value – The paper fills a gap in research about the interactions between vertical and shared leadership dynamics, through a qualitative study, during a change management project.
