It is increasingly recognized that managing organizations with an age-diverse
workforce is a prevalent and significant organizational issue (Avery et al., 2007;
Kunze et al., 2011). Consequently, one of the critical challenges currently facing
HR managers is the effective utilization of the potential of various age groups
and the selection of appropriate human resource management (HRM) tools and
practices (Smolbik-Jęczmień and Żarczyńska-Dobiesz, 2017). Existing research
highlights differences in the approach to older and younger employees. Older
workers are often perceived as reluctant to acquire new skills (Armstrong-
-Stassen and Schlosser, 2008; Ng and Feldman, 2012a; Gross-Gołacka, 2016),
whereas very young employees are considered to lack substantive knowledge
and professional experience (Hysa, 2016). Therefore, awareness of the capabili-
ties and limitations of each group is crucial for achieving high financial and non-
-financial performance, partly due to the complementary competencies of em-
ployees from different age groups (Kilduff et al., 2000).
Most managers in organizations claim to recognize the benefits of multi-
-faceted employee diversity, including age diversity (Kossek and Zonia, 1993;
Kossek et al., 2003). However, few organizations take action to increase the age
diversity of their workforce (Houkamau and Boxall, 2011; Shen et al., 2014).
Nevertheless, the benefits of diversity management are well-documented by
numerous scholars (e.g., Subeliani and Tsogas, 2005). Publications emphasize
that greater diversity can lead to better market and customer understanding, at-
tracting and retaining top talent, problem-solving, and greater organizational
flexibility. Additionally, diversity policies can help employ and retain the most
talented employees, improve productivity, efficiency, and creativity, enhance
staff trust, increase job satisfaction and employee engagement, improve relations
with customers and suppliers, and create a positive company image (Özbilgin
and Tatli, 2011).
One method to increase diversity is the implementation of age-inclusive HR
practices. Age-inclusive HR practices (Kunze et al., 2013), also known as age-
-friendly organizational practices (Appannah and Biggs, 2015) or diversity-
-friendly HR policies (Kunze et al., 2013), aim to overcome age-related barriers,
promote age diversity, and ensure an environment where everyone can develop
their potential regardless of age (Walker, 1997; Taylor and Walker, 1998). This
means that age-inclusive HR practices establish universally accepted principles
of cooperation (Bowen and Ostroff, 2004). Every employee group should have
a sense of belonging to the organization, be treated equally by supervisors when
assigning tasks, and be informed about their work outcomes (Armstrong-Stassen
and Schlosser, 2011). Such a sense of coexistence within the organization is
based on the need for recognition by others, acknowledgment of individual con-
tributions to the common good, and group membership. The sense of organiza-
tional belonging depends on employees’ perception of their group membership.
Differential treatment of employees may lead to perceptions of favoritism
among some employees (Armstrong-Stassen, 2008). Age-inclusive HR practices
can thus facilitate the creation of teams consisting of employees of different
ages, complementing each other with their skills and experience (Walker, 2005a,
2005b), thereby achieving better outcomes. For these reasons, companies facing
an increasing shortage of employees while striving for excellent performance
should consider increasing the age diversity of their workforce through appro-
priate HR practices. However, the literature does not explain in detail the extent
to which organizations implement age-inclusive HR practices, whether these
practices affect the age diversity of employees, and how this relationship influ-
ences organizational performance.
An important factor contributing to the increase in age diversity among em-
ployees, as highlighted in the literature, is the presence of a supportive climate
for such diversity in the workplace. This climate is defined as the collective per-
ception of practices and procedures applied to employees of different ages
(Herdman and McMillan-Capehart, 2010). Furthermore, this climate can mani-
fest in the respect for employees’ dignity and their age diversity (Wegge et al.,
2012; King and Bryant, 2017). Therefore, managers should be interested in cre-
ating a climate that supports age diversity in the workplace, as this can lead to
the integration of organizational processes with employee behaviors and atti-
tudes, ultimately resulting in favorable financial and non-financial outcomes
(Bowen and Ostroff, 2004). The literature indicates the risk that age diversity
among employees may contribute to processes of categorization based on age
group membership (Kunze et al., 2011). Awareness of a supportive climate for
age diversity can be leveraged to mitigate the undesirable consequences of age
diversity, such as discrimination, stereotyping, and related barriers to potential
employee development (King and Bryant, 2017). Enhancing mutual respect
among employees of different ages may be key to increasing age diversity and
improving both financial and non-financial performance (Dovidio et al., 2010).
Thus, the workplace climate can indeed relate to the perception of the strength
with which the group influences company practices, within the social context of
organizational belonging (Avery et al., 2007).
As indicated above, age diversity among employees can positively impact
organizational performance − financial outcomes such as return on assets, sales
growth, and equity profitability (Richard and Shelor, 2002), as well as non-
-financial outcomes like creativity and business decision-making processes (Goll
et al., 2001). Additionally, the literature provides evidence that employees of
similar ages may often compete with each other, exhibiting low task perfor-
mance (Cho and Mor Barak, 2008). Therefore, age polarization among employees
can negatively affect both financial and non-financial organizational outcomes.
It is worth considering the relationship between the degree of age diversity at the
organizational level and the corresponding financial and non-financial results, as
these relationships, particularly when accounting for mediating and control vari-
ables, are not yet fully explored in the literature (e.g., Harrison and Klein, 2007),
especially within the context of domestic literature.
It is hypothesized that a mediating factor in the relationship between age
diversity and organizational performance is knowledge transfer (Skuza, 2018).
According to D.A. Garvin, A.C. Edmondson, and F. Gino (2008), knowledge
transfer is understood as learning from internal and external experts, other teams,
and departments. In the contemporary economy, knowledge is increasingly val-
ued by managers, as possessing key knowledge for the organization can influ-
ence its competitiveness (Shen et al., 2014). However, the transfer of knowledge
among employees of different ages has only recently become a focus of re-
searchers (Kulik et al., 2014). The literature suggests that knowledge transfer
can be significant for organizations with age-diverse employees. Preliminary
empirical evidence indicates that knowledge transfer between younger and older
employees can be valuable, as it allows for leveraging the comprehensive
knowledge of others. However, age diversity can also hinder knowledge transfer,
as individuals tend to prefer interacting with peers of similar characteristics,
particularly sociodemographic traits like age. Therefore, there is concern that
age differences may pose obstacles to communication, collaboration, and
knowledge transfer. Thus, the relationships between diversity and knowledge
transfer, as well as its mediating role in shaping the link between diversity and
performance, require further investigation.
The issue of effectively managing employees of various ages within an or-
ganization is significant both theoretically and empirically due to several reasons:
insufficient research on organizational context − while age diversity is an
area of interest for researchers, the context of the entire organization has not
been adequately studied, particularly in Poland (Shemla et al., 2016);
focus on organizational climate and HR practices − previous research has
concentrated on how age diversity influences the organizational climate and
HR practices; however, the antecedents of diversity have been underexplored,
especially regarding how age-inclusive HR practices and workplace climate
affect age diversity (Armstrong-Stassen and Schlosser, 2011);
overemphasis on financial outcomes − while previous studies have shown
that age diversity improves financial outcomes, non-financial outcomes have
often been overlooked or minimally analyzed (Kunze et al., 2013);
neglect of knowledge transfer − factors that enhance age diversity, such as
knowledge transfer, have been largely ignored (Kulik et al., 2014).
The current state of knowledge on age diversity remains underexplored and
reveals numerous research gaps, despite its importance to all organizations.
Much of the literature has focused on intergenerational diversity (Kirton and
Greene, 2010). Additionally, researchers are examining the process of inclusion
related to social groups or categories within the broader societal context (Marcut,
2014). However, age diversity lacks a clear theoretical framework. This mono-
graph aims to present theoretical frameworks for each variable in the model,
particularly age diversity. The developed research model includes many new and
significant relationships, based on which ten main hypotheses were formulated
and tested.
The findings and scientific considerations in this work contribute to the de-
velopment of the research field and the scientific discipline by:
defining age diversity and management − clarifying what age diversity is and
how it can be managed;
understanding influencing factors − identifying what influences age diversity
and how these variables affect organizational functioning;
measurement tools − confirming the applicability of measurement tools for vari-
ous variables;
effective management strategies − presenting effective ways to manage
younger and older employees by identifying factors influencing age diversity.
The theoretical-cognitive objectives of the study were formulated as follows:
systematizing knowledge in the areas of age diversity among employees, age-
-diversity-supportive workplace climate, knowledge transfer, and HR practic-
es supporting age diversity among employees;
determining the influence of age diversity among employees on organizational
outcomes considering the potential mediation of individual variables;
identifying antecedents of age diversity among employees;
developing a conceptual model of the relationship between age diversity
among employees and organizational outcomes, HR practices supporting age
diversity among employees, knowledge transfer, and age-diversity-supportive
workplace climate.
The cognitive-explanatory objectives of the study were formulated as follows:
investigating the level of age diversity among employees and the application
of HR practices supporting age diversity among employees, age-diversity-
-supportive workplace climate, and knowledge transfer processes in the sur-
veyed organizations;
empirically examining the impact of age-diversity-supportive workplace
climate on age diversity;
empirically examining the impact of HR practices supporting age diversity
among employees on age diversity;
empirically examining the impact of HR practices supporting age diversity
among employees on age-diversity-supportive workplace climate;
empirically examining the mediating role of age-diversity-supportive work-
place climate in the relationship between HR practices supporting age diver-
sity among employees and age diversity;
empirically examining the impact of age diversity among employees on
organizational outcomes: financial and non-financial;
empirically examining the impact of knowledge transfer on organizational
outcomes;
empirically examining the mediating role of knowledge transfer in the rela-
tionship between age diversity among employees and organizational out-
comes;
empirically examining the mediating role of age diversity among employees
in the relationship between HR practices supporting age diversity among em-
ployees and age-diversity-supportive workplace climate as well as knowledge
transfer.
The practical objectives of the study include: formulating guidelines for
practice regarding strengthening age diversity among employees and increasing
its impact on firm outcomes.
The methodological objectives include: confirming the feasibility of using
research tools to measure all variables, especially the variable related to age
diversity.
Therefore, the main objective of the study can be formulated as follows: to
explain age diversity among employees in the context of antecedents and organi-
zational outcomes.
The scientific monograph is divided into five chapters, preceded by an in-
troduction and followed by a conclusion. The first chapter presents the theoreti-
cal foundations of the concept of age diversity among employees. It starts with
a general understanding of employee diversity and highlights its importance not
only in human resource management but also in the broader context of corporate
social responsibility. The chapter also classifies employee diversity, discusses
theoretical foundations of age diversity, and presents theories related to age.
It further emphasizes two approaches to describing employees: generational
context and groups of younger and older employees. The second chapter charac-
terizes the antecedents of age diversity, focusing on age-inclusive HR practices
and a supportive workplace climate. It also highlights the relationships between
these practices and workplace climate. The third chapter discusses the effects of
age diversity at the organizational level, focusing on its impact on financial and
non-financial outcomes and the mediating role of knowledge transfer. The fourth
chapter introduces the research methodology, including methods, sample selec-
tion, variables, measurement, and data analysis. The fifth chapter presents and
interprets empirical findings. In conclusion, the study addresses the scientific
problem and the extent to which the objectives were achieved, identifies main
limitations, proposes practical implications for the business sector, and suggests
directions for further research.
