The terminology and definitions surrounding voluntary activities vary across academic and political discussions (e.g., Wilson, 2000). Each concept of volunteering has distinct meanings and differing characteristics.

In a broader sense, volunteering is a specific and organized form of prosocial action (Strubel et al., 2024). The activity has a longer-term focus, a prosocial intention, and is publicly visible. The following aspects characterize volunteering (Wehner et al., 2015; Wilson, 2000): it is (1) charitable, (2) occurs within an organized framework, (3) could also be performed by another person, (4) is outside of professional obligations, and (5) is unpaid, although expense allowances are usually not excluded. Volunteering contributes to value creation but does not solely follow a classical economic logic, instead marking the transition to a care economy. While typically unpaid, voluntary activities may involve expense reimbursement or small-scale payments. These five criteria differentiate volunteering from paid work, which is defined by payment, professionalism, and contracts (Wehner et al., 2018). Most volunteering occurs within voluntary or civic organizations (Wehner et al., 2015), where paid and unpaid staff often work together following the same organizational aims. This dual presence of paid and unpaid roles within the same organization illustrates the complex nature of voluntary activities.

Simultaneously, there is a growing trend of volunteerism within profit-oriented organizations, often termed corporate volunteering (CV), a term for voluntary activities supported by the organizations themselves, often as part of their corporate social responsibility (CSR) strategies (Gentile & Wehner, 2012). Employees are encouraged to participate in community service during work hours or in their free time, as the companies hope that CV will benefit them by increasing workplace skills and boosting corporate image (Blohm et al., 2012). CV meets the criteria of volunteering but varies depending on its specific form, particularly in terms of: (1) potentially less autonomy, (2) de facto payment, and (3) the risk of instrumentalization (van Schie et al., 2012).

Organizational citizenship behavior (OCB) is another concept related to paid work and embraces various factors, including volunteering for extra work (Organ, 2018). Organizational citizenship behavior goes beyond formal job requirements and is not explicitly recognized by the formal reward system. The concept is characterized by its fully voluntary nature and internal motivation, aimed at enhancing organizational efficiency and the workplace environment (Organ, 2018; Podsakoff et al., 2000). Of the various dimensions of voluntary behavior, only OCB, as a broad construct of volunteering, fully meets the criteria outlined above.

Empirical research confirms a close association between OCB, job satisfaction, and organizational performance (Organ, 2018), underlining the relevance of OCB for organizations. Two additional findings are particularly noteworthy in the present context. First, informational organizational justice — the perceived fairness of the explanations and information provided by authorities, such as supervisors or managers, regarding decision-making processes and outcomes within an organization — is strongly associated with OCB (Colquitt et al., 2013). Second, the presence of role models, such as supervisors and coworkers who display OCB, can foster similar behaviors among employees (Organ, 2018). In addition, it is empirically observable that the cross-cultural differences in the prevalence of OCB align with the country-level variations observed in CV (Meijs et al., 2021).

While OCB and CV involve voluntary actions, OCB primarily benefits the organization internally, whereas CV extends its impact to external community efforts. Both blur the lines between traditional unpaid volunteering and corporate-sponsored initiatives, emphasizing companies’ roles in supporting employee engagement. Consequently, it is important to distinguish between the terms voluntariness and social benefit while highlighting their commonalities. There is a pivotal distinction between voluntary activities performed privately (volunteering) and those within the context of employment (CV). This distinction is crucial when considering the mutual benefit of volunteering for the acting individual and the organization in which volunteering occurs or is promoted. The distinction is discussed in the following.

Volunteering presents challenges, as the tasks may be physically or mentally demanding, and time commitment can lead to increased stress (Hielscher & Nock, 2014; Kals et al., 2020). Additionally, conflicts within the volunteer role, a lack of appreciation, or external misunderstandings can undermine satisfaction and lead to frustration (Kals et al., 2020; Thiel, 2019). Minorities such as migrants are under-represented in volunteering (Hielscher & Nock, 2014). While volunteering is viewed as a privilege of higher social status (Rameder, 2015; Schütt et al., 2024), 39.7% of the German population is involved in at least one voluntary activity that fits the definition of volunteering. However, individuals with lower educational attainment and people with a migrant background are under-represented (Simonson et al., 2022). These trends are explained by the selection hypothesis, which suggests that individuals who are already more socially integrated have easier access to volunteer opportunities. Volunteering structures may unintentionally reinforce existing social inequalities by making it increasingly difficult for individuals from under-represented groups to participate, thus creating self-reinforcing cycles of unintended exclusion and participation (e.g., Ramos & Wehner, 2015).

Research on access to CV programs shows that these sociodemographic factors do not overly influence employee participation. Studies show ambiguous correlations between gender, age, and tenure (Howard & Serviss, 2022), although employees with higher education levels tend to volunteer more frequently (Howard & Serviss, 2022), and top management participates less frequently than other groups (Blanke, 2018).

In addition to the described mutual benefits of volunteering in a paid work context, research shows that CV can also negatively affect participants. Glavas (2016) notes that volunteering as part of CSR can undermine employee engagement, especially when the activity is perceived as an extraneous role rather than authentically integrated into the work context. Volunteers experience identity conflicts or increased role stress, which, in turn, contributes to work-family conflict (Gatignon, 2022).

Theoretical considerations reveal that volunteering encompasses diverse activities, extending beyond the core of traditional volunteering in a private context (mainly occurring in voluntary or civic organizations) to play an important role in for-profit organizations. People’s reasons for pursuing paid or voluntary work are often assumed to be fundamentally different. While it is commonly believed that people work for money and volunteers are driven by “pure” altruistic motives, empirical evidence indicates a pluralism of motives in both contexts (Strubel & Kals, 2016; Wehner et al., 2018).

The functional approach by Clary et al. (1998) aims to explain the differences in people’s volunteering and is supported by extensive international research (Chacón et al., 2017). The definition moves beyond the dichotomy of “altruism” versus “egoism” that initially stimulated and shaped research on volunteering (Penner et al., 2005). The functions are partially self-orientated, partially community-orientated, or a combination of these. Clary et al. (1998) identified six functions in motives for volunteer work:

A person can experience multiple and varying benefits from the same activity (Clary et al., 1998). While all six functions play a significant empirical role, the experiential and value functions are particularly prominent. These two motivations also play a significant role when applying Deci and Ryan’s (2000) self-determination theory to volunteer work, as explored by a Swiss research group. This theory emphasizes personal interest and the pursuit of self-determined action (Güntert et al., 2016).

As described by the career function motive (Function 2 of Clary et al., 1998), volunteering can play a significant role in skill acquisition and career development, which is a central argument in this article. Empirical evidence supporting the career-related benefits of volunteering reinforces this claim (Khasanzyanova, 2017; Liszt-Rohlf et al., 2021). Theoretical frameworks from career development research (see Baruch & Sullivan, 2022), particularly those emphasizing informal learning processes (Peeters et al., 2014), provide further insight into the underlying mechanisms of these processes. These studies highlight that informal learning often occurs through self-directed projects, daily interactions, experiential engagement, and the influence of a program’s informal or hidden curriculum. Such processes are highly relevant in the context of volunteering, for example, within sustainability initiatives in higher education institutions (Gramatakos & Lavau, 2019; Hopkinson et al., 2008). Such informal learning has been recognized as equally important to formal learning for developing employees’ skills (Noe et al., 2014). Empirical findings underscore the significance of these informal learning experiences, with some participants describing their engagement as contributing to broader life experience and the development of personal wisdom (Nekaris et al., 2022).

Clary et al. (1998) state that the list of functions fulfilled by volunteering is not exhaustive and can be extended, a notion that has since been explored and expanded upon in numerous studies. Among these functions, the concept of meaningfulness, as introduced by Hoof and Schnell (2009), highlights the importance of finding purpose through volunteering. Furthermore, the motive of justice accounts for a unique variance in volunteer activities beyond the six established functions of volunteering, as demonstrated by Jiranek et al. (2013). Additionally, the dimension of responsibility has been confirmed as a significant factor through the Scales of the Attitude Structure of Volunteers (SEEH) developed by Bierhoff et al. (2007), further underscoring the multifaceted nature of motivations behind volunteering.

Moreover, specific motives are relevant for individuals who volunteer in a particular field, such as justice-related political motives to volunteer for refugees (Kals & Strubel, 2017). Another example is sensation seeking and public safety as motives for volunteering with the fire department (Kals et al., 2016). Volunteering in this disaster and civil protection sector complements the efforts of professionals and paid disaster services (Freund, 2019) in high-stakes, high-pressure environments (Hagemann et al., 2012; Hagemann et al., 2022).

In a research program, volunteers' unique motivations and challenges were recognized (Freund, 2019; Kals et al., 2020). The study employed a mixed-methods approach to comprehensively understand volunteer motivations in civil protection. Quantitative data were gathered through surveys distributed to volunteers in various disaster management organizations, while qualitative data were obtained through interviews with key stakeholders, including volunteer coordinators and long-term volunteers. The samples included a diverse group of volunteers across different regions and roles within civil protection, ensuring a broad perspective on the factors influencing volunteering. The findings indicate that volunteers in disaster management are driven by a combination of altruistic and self-serving motivations. A strong desire to contribute to public safety and community resilience are common motives, alongside personal growth, skill development, and the fulfilment of a sense of duty. Unlike paid professionals, who may prioritize job security and career advancement, volunteers are more likely to be intrinsically motivated by helping others and the satisfaction derived from being part of a well-coordinated response effort.

Barriers to volunteering were also explored (Freund, 2019; Kals et al., 2020; Thiel, 2019), and the following factors were identified:

Research on the intersection of paid and unpaid work remains limited (see Freund, 2019), although existing data highlight their reciprocal effects (Hatami et al., 2024). We expanded our understanding in this field by conducting a field study on the fire service. The fact that the fire service includes both paid personnel (professional firefighters) and unpaid personnel (voluntary firefighters) served as a quasi-experimental condition. This structure offered a unique opportunity to study the dynamics and motivations of engagement within the same operational context, providing insights into the similarities and differences between volunteer work and paid employment. The study is particularly relevant for questions concerning the transferability of work psychology findings from voluntary employment to paid work.

Our online study (N = 1804) involved volunteers (N₁ = 1549) and paid fire service personnel (N₂ = 255; Kals et al., 2016). Clary et al.’s (1998) volunteer functions inventory (VFI), enlarged by including the fireman-specific function of sensation seeking, was transferred to employed firefighters as a redesigned paid functions inventory (PFI). Although perceived differences exist between the groups and their self-image and construction of “the other”, volunteer and professional firefighters share similar motivational structures. The VFI and the PFI show structural alignment in how both groups are motivated by factors such as experience, values, self-esteem, and social adjustment (Table 1). Even though there are statistically significant differences between both groups, the effect sizes of these differences are predominantly small.

Both groups report high levels of (job) satisfaction. This satisfaction is strongly influenced by shared values, such as the desire to help others, and a balanced perception of effort and reward. The fundamental difference lies in compensation. Professional firefighters are paid for their work, which introduces an additional motivational factor related to securing their livelihood (the pay function), whereas volunteers are not compensated.

The results indicate that the motivations for volunteering and paid work are similar. Intrinsic motivations, expressed in the VFI in the form of the value and experience functions (see Güntert et al., 2016), play a vital role. Volunteer work is hindered primarily by inadequate framework conditions and, to some extent, by insufficient social recognition rather than lack of pay. This finding corresponds to the notion of a complex person who conducts their activities in a self-determined but socially integrated manner, realizing prosocial intentions and striving for self-realization. These results challenge the homo economicus model (Kals, 1999). This model assumes that monetary self-interest and the pursuit of personal advantage are the primary drivers of human behavior. According to this model, individuals engage in social interactions to maximize their subjective utility. However, the motivations for paid and voluntary work have similar characteristics, and these engagements are all motivated by multiple factors, with meaningfulness playing a central role and financial incentives alone not being the decisive factor.

A key question must be answered before deciding whether volunteering should become a new task for HR development: Are there useful spillover effects between unpaid and paid activities? Spillover effects illustrate the close psychological connection between different types of activities (Pollack, 2023). The concept refers to a phenomenon where changes in one behavior or context influence subsequent behavior or contexts that can be positive or negative (Truelove et al., 2014).

Pollack’s (2023) study is situated at the intersection of occupational and volunteer research, examining the potential spillover effects between OCB in paid employment and volunteering in non-profit organizations. Based on the idea that behaviors in one life domain can enhance similar behaviors in another domain, the study explores how actions in a professional context may extend into voluntary activities and vice versa. Previous research has indicated significant synergies between work and private life, particularly regarding behavioral spillovers, where similar behaviors in one domain can influence behaviors in another.

The primary research question is whether positive spillover effects exist between OCB in professional settings and volunteering in non-profit organizations (Pollack, 2023). The study further investigates the temporal stability of these effects, the perception of them from personal and external perspectives, and whether differences exist between individuals engaged in volunteer activities and those who are not. Additionally, the study seeks to explain these spillover effects by exploring factors such as social responsibility, individual resources, and value congruence.

The study employs a multimethod approach, including longitudinal and cross-sectional designs and qualitative interviews. This comprehensive approach allows a robust analysis of spillover effects across different contexts and over time. The sample consists of employed individuals who are engaged or not engaged in volunteer activities within sports clubs and non-profit organizations. The pre-study included 432 participants, while 434 were involved in the generalization study. Data was collected using standardized questionnaires that measured various aspects of OCB and volunteering, alongside semi-structured interviews with a subset of participants. The study utilized validated scales for measuring social responsibility, competence, and value congruence, ensuring the findings’ reliability and validity (Pollack, 2023).

The study identified positive spillover effects between OCB and volunteering in non-profit organizations, particularly within equivalent dimensions of engagement across contexts. The strongest spillover effects were observed for helping behavior and conscientiousness, with these behaviors being consistent across professional and volunteer settings. However, no mediating role was found for social responsibility or competence in these spillover effects. The positive spillover effects cannot solely be explained by personality factors, such as social responsibility as a personality trait (Pollack, 2023). Overall, the study findings suggest that positive spillover effects of helpfulness and simplicity are based on the consistency motive in terms of self-perception. In contrast, spillover effects of initiative are underpinned by mechanisms of self-efficacy. Evidence of spillover effects between OCB and volunteering in non-profit organizations demonstrates the benefits of both forms of engagement for organizations.

Volunteering typically occurs within organizations. Consequently, in scientific research, efforts are being made to apply existing models and findings from work psychology, which have been developed and used primarily for paid work, to the organization of voluntary work to promote its professionalization. One of the main research questions within work psychology concerns the underlying conditions and promoting factors of efficient work outcomes, including job satisfaction.

The analysis of voluntary activities in organizations has applied models and theories used for paid work. The first of these approaches was Hackman and Oldham’s (1975) job characteristics model, a foundational framework in work psychology. The model includes the five core job dimensions — Skill variety, Task identity, Task significance, Autonomy, and Feedback — essential in creating conditions that foster a sense of meaningfulness, responsibility, and quality of work.

Empirical research supports the applicability of the job characteristics model to voluntary work (Thiel, 2019). Overall, correlations of up to .41 have been found between the task characteristics of voluntary work and satisfaction (Millette & Gagné, 2008). Task variability, task significance, and feedback are crucial for volunteers (Güntert, 2015; van Schie et al., 2015). For instance, understanding the impact of their work — knowing that their efforts make a meaningful difference in the lives of others — can significantly enhance volunteers’ intrinsic motivation and performance outcomes. The significance of the task in volunteer work is often directly linked to the satisfaction derived from the volunteer knowing their contributions are valuable and appreciated. Volunteers often seek roles that provide a sense of purpose and fulfilment, and when these needs are met, they are more likely to remain engaged and committed to the organization. Moreover, feedback plays a vital role in volunteer settings. Volunteers who perceive their roles as important and receive regular feedback are likelier to report higher levels of job satisfaction and motivation (Güntert, 2015; van Schie et al., 2015). Job satisfaction and motivation are vital in volunteer contexts, where there is no financial compensation, making psychological and social rewards crucial. Volunteers, like paid employees, benefit from constructive feedback, which helps them feel competent and valued. In line with theories and empirical findings on feedback rules in organizations (see Anseel & Sherf, 2025), such feedback reinforces volunteers’ sense of accomplishment and encourages continued engagement by validating their efforts and contributions. Consequently, a lack of appreciation and recognition can negatively impact volunteer retention and increase the risk of disengagement (e.g., Kals et al., 2020). The previously mentioned study on volunteerism in civil protection and disaster management showed that the principles of the job characteristics model are highly applicable to the design and management of volunteering (Freund, 2019).

However, the relatively few existing comparative studies indicate potential differences in their significance between paid and volunteer positions. Volunteers prioritize task significance and variety, while autonomy is less crucial than in paid roles (Millette & Gagné, 2008; Wehner et al., 2006). However, autonomy in volunteering — regarding time, place, purpose, and nature of the work — remains essential (Wehner et al., 2006). This fact emphasizes the need to view volunteering as a distinct phenomenon, despite some overlaps, and not to assume the findings from paid work are generalizable to voluntary work.

The empirical findings presented so far suggest that volunteering has a lot of desirable consequences for individuals and great potential for organizations. In the following, we summarize these findings, complement them with additional ones and derive implications for volunteering within HR Development.

The psychology of volunteer work, particularly through the efforts of Wehner (e.g., Wehner et al., 2018), has been crucial in elevating the recognition of volunteering within research. Traditionally, societal and academic focus has concentrated on paid work, reflecting an implicit norm emphasizing self-interest and monetary motives. This focus may inadvertently reinforce a reductionist view of humans as primarily rational and self-serving, potentially overlooking other meaningful and less directly “self-serving” motivations. Such a simplified image of human behavior may persist because it satisfies the human desire for clarity and order.

In contrast, research shows that volunteer work is as complex and valuable as paid employment, demanding further exploration. How does volunteering shift throughout one’s life? What challenges arise in balancing volunteering with family and career commitments? Why do some people choose not to volunteer, and what barriers exist? These questions have implications for HR development, suggesting the need for a broader understanding of engagement.

Adopting a life-course perspective can capture the dynamic nature of volunteerism, as motivations change and time constraints fluctuate, particularly during life’s “rush hour” when career and family demands peak. The division between paid and unpaid work is often more fluid than perceived, with activities spanning from formal employment to compensated volunteerism, each contributing to a sense of fulfilment and social participation.

Bauhardt et al. (2024) offer an inclusive, overarching framework that can help reconcile the competing notions of “paid” versus “unpaid and voluntary” work, highlighting the intent and meaning behind activities that contribute to a sense of purpose. Doing so makes it possible to re-categorize these activities within a more holistic and inclusive consciousness. All forms of work, whether paid or unpaid, can be meaningful and fulfilling. Moreover, volunteers perceive their “voluntary non-profit activity as a form of work” (Mösken et al., 2010, p. 49), although volunteering is much more than unpaid labor (Wehner et al., 2006). Promoting this inclusive understanding can shift societal and individual perceptions.

This understanding aligns with the humanistic tradition in psychology, particularly the ideas of Rogers (1979), which frame individuals as growth-orientated, self-reflective, and responsible. Volunteering fits into this framework, representing an expression of the human drive to be active and accountable as people take responsibility for their contributions to society. A humanistic approach fosters attitudes of empathy, authenticity, and unconditional positive regard, ensuring that volunteer work is not instrumentalized but supported for its intrinsic value. This approach fosters conditions where all parties — volunteers, organizations, and communities — benefit, achieving “win-win-win” outcomes. Embedded in this humanistic understanding, volunteering in organizations can be seen as a high-potential task for HR development as a discipline and practical tool, linking science and practice.