1. An Exponential Trend since the Early 2000s
Within the Scopus database, the term human flourishing was used for the first time in 1969, in the article Human Flourishing: On the Scope of Moral Inquiry 
. It is is classified under the arts and humanities field, which from an ethical and even religious point of view, interacts with psychiatry, as it poses the question of what humans need to flourish. The term appeared only a few times during the next 25 years, until 1994, when there were only seven documents featuring it in Scopus.
The first significant growth in the use of the term can be observed during the late 1990s. Between 1995 and 2000 alone, 27 more documents appeared, which represented almost four times more documents in those last 5 years than in the previous 25. Figure 1 shows the exponentially rising phenomenon observed during the following 20 years, highlighting some peaks or incremental points for the periods when the total academic production around human flourishing occurred the most. The first spike happened between 2004 and 2005, when the number of documents published in Scopus went from 11 to 24. A second rise took place between 2008 and 2009, when publications increased from 35 to 62. Similar significant growth spurs took place in 2013, 2016, and 2018.
Figure 1. Human flourishing academic productivity, by year, faceted by Scopus subject areas.
As can be seen in Figure 1, such evolution in academic productivity created a curve that is more clearly appreciated in the total document count, but also in more specific subject areas. The fields of social sciences, first, and the arts and humanities, next, were the two areas where most of the document production occurred and which also maintained an important level of citations. In fact, some of the peaks previously identified took place in these subject areas, the most important occurring in 2005, when productivity in the arts and humanities increased from 5 to 16 documents, and from 5 to 10 documents in the social sciences.
A closer examination of the documents from these two most productive subject areas reveals the most cited documents in the social sciences to be: Flourishing Across Europe: Application of a New Conceptual Framework for Defining Well-Being 
, with 524 citations; followed by
A Participatory Inquiry Paradigm 
, with 510 citations, and Introduction: Contributions to the Discipline of Positive Organizational Scholarship 
, with 191 citations. These three articles, written by different researchers, claim the benefit of focusing on subjective experiences to measure realities as different, as society as a whole, research epistemologies, and organizations, respectively.
Among the documents classified under the arts and humanities, the most frequently cited are: the book Why Things Matter to People: Social Science, Values and Ethical Life 
, with 542 citations; again, the article by Huppert and So 
—also classified as social sciences—with 524 citations, and the article Mental health in adolescence: Is America’s youth flourishing? 
, with 311 citations. Although these documents also elaborate on the importance of subjective experience, a comparison among them will show a focus on the impact that flourishing in daily human lives has as a source of dignity.
Although featuring a lower number of publications than the social sciences and the arts and humanities, the field of psychology can be considered as having a greater impact due to its number of citations. This trend began with Barbara Fredrickson’s article The role of positive emotions in positive psychology: The broaden-and-build theory of positive emotions 
, with 6412 citations at the time of data collection. The article is by far the most frequently cited document of the sample. Opposing traditional psychology, which used to prioritize the study of mental diseases, traumas, and deviations, Fredrickson argued in 2001 that there was important empirical evidence of the effect of positive emotions on all aspects of human life, to the extent of providing strength and resilience in the face of adversity.
The relevance of psychology in the number of citations is constant throughout the sample, as this field contains six of the ten most cited documents: 
with 1269 citations; again, Fredrickson, but now with Losada 
, with 1182 citations; 
with 879 citations; 
with 524 citations; again, Keyes 
, with 311 citations. Some of these articles, however, are also classified under the social sciences and/or the arts and humanities fields. Following the approach first used by Fredrickson, all of the most cited psychology documents develop the idea of a change in perspective, proposing a focus on positive aspects of mental health to achieve individual and collective well-being.
After psychology, but thematically close, medicine is the next subject area in number of documents and citations. Its most cited articles use the term flourishing to refer to mental health, in relation to desirable characteristics in a population 
, as well as developing quantitative studies, which use metrics, such as the Flourishing scale type 
Finally, it is very important to note the variety of subject areas that make use of the concept of human flourishing. Although with fewer academic documents published, a constant and long use of the term can be observed, since the year 2000, in areas like business and management, nursing, economics and finance, and environmental sciences. The relation of these four subject areas with a concept born in between the arts and humanities and psychology is quite unexpected. Thus, by reaching such diverse disciplines, the concept of human flourishing is proving to be transdisciplinarily fertile.
2. The Dissemination of the Concept
For a deeper study of the evolution and internal composition of the human flourishing concept, a longitudinal analysis was chosen. Based on the above findings, three time periods were established: the first one starts with the first document of the sample, published in 1969, and covers up until 2004, when the exponential trend began; the second one captures the consolidation of the exponential trend, from 2005 to 2015; the last period tracks the academic production during the last 5 years. The data was processed using the thematicEvolution function of the bibliometrix package, which filtered the 250 most frequent keywords, with a minimum of 5/1000 frequency of a keyword to appear within a cluster. The results are plotted in Figure 2, where the clusters are located in a Cartesian coordinate system, with Callon’s centrality as the x axis and Callon’s density as the y axis. Each cluster is labelled with its three most important keywords, along with the frequency that each keyword reached; however, there were other keywords which were not depicted, due to display limitations.
Figure 2. Researchers’ Keyword thematic evolution map clusterized items taking into account the 250 most frequent words overall, with a minimum of 5/1000 frequency and deploying the three most valued labels. The size of the clusters is proportional to the volume of keywords it contains.
Figure 2 also shows three different configurations for each period. Between 1969 and 2004, only three clusters emerged. The first one is represented by the keyword flourishing, with high centrality and high density, and it condenses most of the keywords in that period. It also contains the keyword virtue and is very close to another cluster, represented by ethics. Because of their high centrality and density, these two clusters are located at the motor themes zone. A third cluster is identified, equally comprised by liberalism, perfectionism, and utilitarianism, featuring a slightly lower centrality and density, and fully located in the basic themes zone.
Within the second period, it is possible to identify a high number of clusters. The one labeled as flourishing is seen to have greatly decreased in density, while only slightly in centrality, which now places it in the basic themes zone. It is important to note that the rise in the number of documents analyzed during this period is also consistent with the variety of keywords contained in the clusters. In the case of flourishing, the presence of keywords, such as well-being and happiness, stands out; this offers an updated view of the term, which is now more concerned with the subjective perception of happiness and mental health, albeit in an increasingly individualistic way (keywords not plotted but appearing together within the cluster are: positive psychology, subjective well-being, mental health, autonomy, resilience, health, and individualism).
Also within the basic themes, there is another cluster closely accompanying the one labeled as flourishing in the second period. It reveals the classical ethical view, previously identified in the same cluster as flourishing. Labeled under the keyword virtue, this cluster contains many keywords that belong to Aristotelian philosophy, for example, eudaimonia, among others (keywords not plotted but appearing together within the cluster are: ethics, justice, sustainability, practical wisdom, work, politics, and recognition). Another keyword therein is sustainability, which can be interpreted as an update of the Aristotelian concern with immanent justice.
However, within the second period, a new cluster appears in the motor themes zone, under the name of philosopher Martha Nussbaum. The cluster is located in a privileged place, with significantly high density and centrality, which makes it the clearest motor theme for the period. The cluster contains keywords, such as equality and enhancement, as well as others such as liberalism, previously identified in the first period (keywords not plotted but appearing together within the cluster are: identity, institutions, culture, dignity, human capabilities, liberalism, and political). Indeed, the cluster holds multiple semantic connections with the one seeming to be, albeit partly, the motor theme (the capabilities cluster, which also contains the words religion and economics).
Another cluster surfaces between the motor and the niche themes zones, comprised by the keywords emotion, positive emotion, and meaning. It is important to note that, although not apparently seen, the cluster also contains the keyword neuroscience, which is part of the motor, or even niche, theme—as it is placed in the middle—and which takes into account how to achieve motivation and meaning in life. In fact, the term is quite close to the education cluster, which is fully situated in the niche themes and contains keywords associated with common experiences and contemporary claims, allegedly needed to flourish as a society (keywords not plotted but appearing together within the cluster are: Islam, democracy, feminism, and love).
The third period features fewer but larger clusters, where the number of documents with the keywords flourishing or human flourishing rises sharply, increasing from 6 in the first period to 191 in the second and 508 in the last one. The cluster labeled as flourishing recovered a fraction of its density and centrality relative values, although it remained within the basic themes zone. Along with flourishing, other terms, such as well-being and positive psychology, among others, can also be seen (keywords not plotted but appearing together within the cluster are: mental health, depression, psychological well-being, resilience, subjective well-being, mindfulness, and COVID-19). Most of these keywords remain from the second period, keeping their high centrality through the third one and showing an increasingly frequent correlation with flourishing and positive psychology.
Another cluster within the third period is the one equally labeled as religion, sustainability and values, which is also located in the basic themes zone, with high centrality (keywords not plotted but appearing together within the cluster are: human rights, leadership, social justice, and spirituality). Of course, these keywords appeal to different issues, but all of them express claims related to the ethical framework of human flourishing, understanding religion in relation to spirituality, which constitutes a less doctrinal demand of the experience.
At the center of the motor themes zone is the word virtue, with practically the same keywords identified as basic themes in the second period. The cluster grows from 40 keywords to 55 and contains mainly terms from Aristotelian ethical philosophy (keywords not plotted but appearing together within the cluster are: capabilities, eudaimonia, education, disability, health, justice, and meaning). Nussbaum’s capabilities approach is also found within the cluster, maintaining its presence in the motor themes zone, but losing its role as a cluster representative.
Although there are no clusters found entirely in the niche themes zone during the third period, two cross over, partially. The most important one is the cluster labeled as happiness, featuring high density and referring to terms such as life satisfaction (keywords not plotted but appearing together within the cluster are: public health, psychology, optimism, assessment, intervention, policy, and purpose in life). Despite its allegedly highly subjective approach, it also includes keywords such as public health, intervention, and policy, which help the cluster to be understood in a more social and committed way.
3. Human Flourishing Keyword Network Relations
Having analyzed in detail the evolution of the use of the concept, the researchers will focus on the network correlations as a whole, much like a snapshot, enabling a view at a glance of all the connections between keywords. With that purpose, a network analysis was performed, clustering the keywords through the modularity algorithm, and taking into account their frequency of co-occurrence as the weight of the edges. Figure 3 shows the resulting network after removing all keywords with a degree below 50.
Figure 3. Researchers’ keyword network clusterized by their modularity class. The clusters are represented by the different shapes and colors of the nodes; the width of the edges shows the frequency of co-occurrence between a pair of keywords; the size of the nodes is their weighted degree, and the size of the labels represents the betweenness centrality. The network was filtered for keywords with a degree range higher than 50. The plot was drawn with Gephi software.
In the center, there is a cluster in the shape of a circular node, which features both the highest node population (22) and the widest and strongest connections. It contains the two most frequent keywords in the whole data sample: flourishing and well-being. Along with them, there are keywords, such as happiness, positive psychology, mental health, psychological well-being, mindfulness, and life satisfaction. From the set of connections, it can be affirmed that the psychological approach is the closest to the human flourishing concept, highlighting, at the same time, keywords that emphasize individual and internal aspects of well-being and life satisfaction, for example mindfulness, emotion or positive emotion, motivation, resilience, and, clearly, subjective well-being.
It is quite interesting to note that, while precisely, the terms that imply the most negative emotions in the whole dataset (anxiety and depression) are strongly connected with a few of the terms in the main cluster (specifically flourishing, well-being, and mental health), they are identified as a separate, tiny cluster with hexagonal nodes—made up only by these two nodes—and located in the middle of all the positive terminology from psychology.
Second to flourishing and well-being is the pentagonal cluster, made up of 14 modules and featuring virtue as its main node. Virtue is the second most important keyword in the network and appears in strong connection with ethics, another highly relevant key term therein. Without a doubt, the cluster alludes to Aristotelian philosophy, as it contains terms like Aristotle, wisdom, practical wisdom, and common good; it also points to the ideas of other philosophers, such as Thomas Aquinas, which makes the relation with keywords, such as theology, quite logical. Within the cluster, the precise term is related to love, a highly atemporal and universal reference, which, in terms of semantics, can easily connect with many other clusters. Finally, although it belongs to the Aristotelian cluster, justice is another keyword that is also highly connected with the triangular nodes cluster in the network, which features most of the keywords from the capabilities approach.
Effectively, the triangular nodes cluster, made of seven nodes, represents the constellation of the capabilities approach, as it contains terms such as social justice, human rights, equality, and human dignity. It is important to note that, unlike the flourishing cluster, which is dominated by internal and subjective perspectives—highly characteristic of the positive psychology movement—these triangular nodes refer to highly social and external qualities. This fact confirms that the capabilities approach plays a complementary role in the academic literature on human flourishing, addressing social and mostly external issues, which are barely present within the psychology cluster.
Finally, the square node cluster, consisting of 12 nodes, is quite extensive and spread out throughout the network. Its main nodes are education, meaning, religion, values, and community. These keywords mediate between the more internal concern of the psychology area, through keywords, such as meaning, values, spirituality, identity, or autonomy, and the more external and ethical common issues addressed by the capabilities approach, such as education, community, disability, culture, and morality.
4. The Pathways of the Human Flourishing Network
The betweenness centrality is an alternative measure to understand a network, not just by its terms’ frequency of appearance, but by the way in which more nodes connect better and faster. In the case of this human flourishing network, they will be the keywords and approaches that can connect different trends, playing the important role of mediators within the whole database.
The first keyword whose weighted degree stands out is eudaimonia. Although it features a lower absolute frequency of appearance than that of keywords such as happiness, positive psychology, Aristotle, or mental health, the word obtains a very high position when ranked by its betweenness centrality. As is well known, eudaimonia is a term of Greek origin, introduced by Aristotle, yet as can be seen from the analysis, its capacity to be used in different contexts surpasses the strict context; despite its being one of the capital terms in the field of ethics, eudaimonia was identified as belonging to the main cluster and being well connected with keywords, such as practical wisdom, happiness, or flourishing, but also as reaching a wide variety of terms, such as health, sustainability, work, depression, spirituality, environmental ethics, and liberalism.
Another keyword whose weighted degree position also stands out is ethics, which as is the case with eudaimonia, comes from a classical philosophical approach, yet connects truly well with most individualistic terms of the network, such as subjective well-being, happiness, life satisfaction, or spirituality, and with the most common and external concerns, such as economics, education, disability, justice and social justice, human rights, and common good, among others. Furthermore, ethics is highly connected to certain keywords, such as mental health, quite a specialized and specific term that does not bear connection with many others.
Precisely by looking at the opposite phenomena, that is, at the terms that have a high weighted degree but a lower betweenness centrality than expected, other valuable observations can be made. The first one is that, although positive psychology has more connections and even more betweenness centrality than capabilities, proportionally the last one is more efficient when connecting different keywords. Along with positive psychology, other keywords with an important difference between these two values are mental health, happiness, and, more surprisingly, anxiety and depression. All these relations denote keywords used in specific fields that are not commonly used in research around human flourishing, so they will never be representative of the whole network.