**5. Conclusion and discussion**

As argued in the Introduction, contemporary challenges (e.g. distrust, pace of change, uncertainty, broader societal orientation, sustainability goals) call for a shift in leaders' mindset, more than for improved skills and abilities (skillset). How such a shift in mindset – a transformation of leadership style – can possibly be achieved is therefore an important practical and scientific question [10–12].

The findings of the three studies suggest that the studied nature-based training program does foster more purposeful, authentic leadership. This is an example of a shift in mindset, as the components of authentic leadership, rather than learning a particular skill, reflect changes in thought and behavior: a clear self-concept, focus on moral standards, beliefs, and values, an empathetic listening attitude, and openness and honesty towards others. Therefore, it seems plausible that a nature-based leadership transformation program could be a suitable tool to achieve the inner development goals (IDG). As such, the findings suggest that commitment to authentic leadership would enhance leaders' ability to respond to current challenges. Greater ethical responsibility and transparency on the part of leaders could lead to greater social responsibility and environmental stewardship, as well as help, build public trust.

In the results of particularly study 1 and 3, the emotional content of the experiences and memories stands out. When participants describe their peak experiences during the trail, they often do so in terms that suggest underlying emotions. Peak experiences are positive, emotionally, and cognitively intense, stand out and have the potential to fuel lasting change in subjects [55]. In addition, during the interviews, participants relived personal, important, and emotion-laden moments, not seldom accompanied by tears in their eyes. Typically, emotions related to a past event, and identified as important in the mind, can inform current feelings, thoughts, and actions [101]. Therefore, emotional experiences must be recognized as an important means of generating insights that can bring about change - learning new things and changing mental dispositions and behaviors. With little room for emotion, however, leadership development programs predominantly opt for cognition-based trajectories, and again, mostly in workplace/classroom settings [12, 40–42]. A meta-analysis of 335 samples [102] estimated the effectiveness of leadership training over many years (1951–2014) and organizations. Their analysis indicated that leadership training is effective in improving affective, cognitive, and skills-based outcomes. Thereby, the researchers suggested that the most effective training programs include all three - cognitionbased - delivery methods, that is information-, demonstration- and practice-based

methods, preferably performed at a location that is on-site. Only in one sentence did they mention that "future research should examine whether affective content can improve affective outcomes to a greater extent" ([102], p. 1701). Thus, very little has been written about the role of emotions in leadership training, and there is an unavoidable lack of findings on the results of using emotion concepts to guide leadership development research. It leaves us with unanswered questions about how leaders can develop their leadership capabilities through emotional experiences. This gives rise to the suggestion that perhaps the most fruitful way to innovate leadership development is to incorporate emotional concepts to address the root causes of learning in leaders.

Of course, self-report data should be appraised critically when it comes to drawing inferences about how effects are brought about, as the way people perceive how things work might be different from how things actually work, and people are not always necessarily honest. Yet, for some findings, it is hard to imagine that self-reports produce artifacts, such as the finding that leaders often recall episodic memories reflecting intense nature experiences when they face challenges at work.

Participants reported they had rediscovered their 'true nature' in stillness. Afterward, as suggested by the interviews, they regularly felt this stillness inside, creating overview and insight, and radiating peace of mind. This mindset shift goes beyond the benefits of well-being and spiritual growth, which are more focused on the self than on others, as documented by research on nature and spirituality [60, 63, 71]. A fruitful area of future research would be to examine how, by what psychological mechanisms, unfamiliar challenges in a natural environment influence changes in leadership style. Perhaps, stronger feelings of empowerment and self-confidence are important mechanisms.

Qualitative research is usually not used for identifying cause-effect relationships. Conclusions relying on findings from reports and interviews could be seen as speculative. Yet, in the studies' context, self-report measurements are perhaps more accurate than a standard interpretation would suggest. For example, some participants perceived a specific wilderness experience as a defining moment, evoking thoughts, reflections, and intentions, and subsequently recalled that moment during important events as a leader. By assigning this meaning to the experience, framing it as an important moment, and storing the memory as a tag that denotes rich associations and is connected to behavioral intentions, they made the experience a trigger for their mindset shift. Thus, the act of perceiving a cause-effect relationship can constitute a cause-effect relationship. Following this reasoning, as participants believe wilderness experiences, storytelling, and unfamiliar challenges change them as leader, it is highly likely that these indeed contribute to leadership style change.

Furthermore, this research is leader-centric, focusing on the intentions and behavior of individual leaders. However, leadership involves a dynamic social interaction within a particular situational context. The organizational context has not been part of this research. Hence, the influence of this context on the sustainability of changed leadership style requires further research. It could, for instance, be interesting to investigate to what extent the change of leadership style is valued in organizations dominated by millennials.
