“Positive Relationships” and their impact on wellbeing: A review of current literature

life span development, positive relationships, social relationships, wellbeing Positive relationships are widely considered to be one of the pillars of wellbeing. Their boosting effect on emotional and physical health has repeatedly been documented by experimental and longitudinal studies. Despite their instrumental role, the existing literature does not offer systematic observations of their nature and characteristics. In this paper, we aim to explore the specific characteristics of positive relationships. We conducted a thorough research of the existing most recent literature and grouped our findings according to the following two research questions: (a) the kind of relationships that are positive in people's lives and, (b) the way positive relationships relate and support well-being. Our findings suggested that specific relationships are examined with respect to different age groups, e.g. peer relationships in adolescence or marital relationships in adulthood. All relationships described as positive at each developmental stage are correlated with wellbeing in various ways. Beyond the characteristics of people and the way they relate, relationships seem to contribute to wellbeing by sharing positive moments and events, being supportive with respect to autonomy and showing an attitude of interest and emotional engagement. In conclusion, we argue that while relationships seem to contribute to wellbeing, there is not yet an exhaustive list of ingredients that make the relationship “positive”. We suggest new ways to enhance the study of positive relationships as well as possible variables that have not yet been examined and could possibly enhance our understanding of positive relationships and their influence on wellbeing. CORRESPOND ENCE

It is widely accepted that social relationships and contacts are an important part of people's lives. People are primarily social beings who seek physical contact with other people as well as strong emotional ties. Social relationships have been indispensable in the development of our species and their role in human survival has been widely documented and generally accepted (Easterlin, 2012). The opposite is also true; lack of social ties and connections are considered a threat to human survival. Animal and human research points to a set of neural regions, that are involved in detecting and responding to impending danger or threat, including the threat of social disconnection (Eisenberger & Cole, 2012).
The importance of social relationships is demonstrated by their impact on human general functioning and physical health. The World Health Organization (2002) recognizes social relationships as an important social determinant of health throughout our lives. Starting in the mid-1990s, emerging literature on Health Impact Assessment has demonstrated that whether people are healthy or not, is determined by their circumstances and environment. Social support networks -i.e. greater support from families, friends, and communities are one of the factors that determine health on an individual and community level (WHO, 2002).
Admittedly, social relationships influence people on many levels and in many ways. Over the last decade, a multitude of research findings highlighted the fact that social relationships are closely tied to longevity, physical health, professional success and wellbeing (Holt-Lunstad & Smith, 2012;Keyes, 2007). Specifically, one of the ways in which social relationships influence physical health is through social networks since people seem to adopt healthy or harmful habits, create close interpersonal relationships and find work through their social network (Christakis & Fowler, 2009;Christakis & Fowler, 2008). People who are more socially active and experience more supportive and empowering relationships have better mental health, higher rates of subjective happiness, and lower rates of disease and mortality rates (Cohen & Syme, 1985;Collins et al., 1993;Kawachi & Berkman, 2001;Lakey & Cronin, 2008;Miller et al., 2011;Sarason et al., 1997;Seeman, 2000;Uchino 2009;Uchino et al., 1996;Uchino et al., 2016;Vaux, 1988).
Regarding the link between longevity and social relationships, a meta-analysis of 148 prospective studies  from North America, Europe, Asia and Australia explored the factors that influence longevity and mortality rate in an accumulative sample of 308.849 people. It revealed that social support had a total effect of .5 on a decreased mortality rate. The effect of social support of decreased mortality was significantly greater than other factors such as lack of smoking, alcohol consumption or obesity that are well known by their positive effects on longevity and lead to decreased mortality rates worldwide (Holt-Lunstad & Smith, 2012). It is important to note that the abovementioned study described social support as the support the individual receives by his or her close relationships and his or her communal life. The researchers did not include in their methodology any form of evaluation of the quality of social support.
In terms of the available explanations regarding the link between longevity and social support, there are currently two most accepted theoretical models: (a) the Stress Buffering Hypothesis and (b) the Main Effects Model (Kawachi & Bergman, 2001). According to the Stress Buffering Model, people who experience multiple stressful life events are better equipped to cope with the stressors when they are supported by others; hence social relationships are a good coping tool against the negative effects of stress (Cohen & Wills, 1985). On the other hand, the Main Effects Model suggests that social relationships create an environment in which people build behaviors and habits that are protective to one's health (e.g. taking routine medical examinations, avoiding bad habits such as alcohol consumption) and, additionally, they experience a sense of belonging that shield individuals against the imbalances that lead to psychological distress (Cohen, 2004;Cohen et al., 2000;Kawachi & Bergman, 2001;Thoits, 1983).
The beneficial effect of social relationships is also highlighted by the work of social psychologists that investigate wellbeing and have repeatedly demonstrated that positive social relationships lead to higher levels of wellbeing (Keyes, 2007;Lyubomirsky et al., 2005;Seligman, 2011).
Consequently, in all theoretical models, the ability and the way people create relationships are related to wellbeing. For example, Ryff' s Six -factor Model of Wellbeing (Ryff, 1989;Ryff & Keyes, 1995) stipulates that people score high on wellbeing when they report having warm and satisfying relationships, trust others, care for other people's well-being, are capable of empathy, tenderness, emotional proximity and experience the reciprocity of human relations. On the contrary, a person who has few close and trusting relationships has difficulty being open, warm and showing interest in others, is isolated and frustrated by her relationships and is not willing to make compromises (Kim et al., 2016).
Similarly, in Seligman's PERMA model for "flourishing", "Positive relations" defined as authentic association with others, is one of five pillars of wellbeing. The model posits that achieving meaning and purpose in life is inextricably linked to close and meaningful relationships (Seligman, 2011). Christakis and Fowler (2009) suggest that the chances of being happy are increased by 15% if someone is directly linked to a happy person and 10% if someone's friend has a happy friend. This finding is impressive considering that an increase of 10,000 euros in one's income in 2009, was responsible for just 2% of the increase in happiness.
However, it is important to consider exactly what is being investigated when studying social relationships. Social scientists investigating close relationships examine them by asking questions such as "who do you discuss important issues with?" Or "who do you spend your free time with?" They seem to define in advance the quality, the content and the characteristics of the relationship. About half of those referred to as social relationships are friends, while the other half includes a wide range of diverse relationships, such as spouses, erotic partners, parents, siblings, children, colleagues, club members, neighbors, etc.
In the context of positive psychology, the concept of positive relationships is presented as something that we all understand what it is and, therefore, we do not need to further define. Different adjectives such as productive, positive, close, meaningful, healthy, etc. are used in the literature oftentimes interchangeably. It seems that "positive relationships" is used as an umbrella term that includes all form of social connections, yet this is never clearly stated or acknowledged. We could, therefore, argue that existing research has highlighted the importance of positive relationships, nevertheless, there is still a great deal of ambiguity regarding their form and characteristics, and how they are created and maintained during the lifetime. Additionally, it remains unclear how positive relationships support wellbeing and whether there are other variables that mediate or moderate this relationship. This paper is a literature review aiming at exploring the following research questions: a) What kind of relationships are positive in people's lives? b) How do positive relationships relate and support well-being?

Methodology
In order to investigate the above research questions, we conducted a literature review with an emphasis on the most recent publications. Specifically, we examined research published in English-language scientific journals retrieved from Psych Info and Medline electronic databases from 2010 onwards. The keywords used were: social relationships, healthy relationships, positive relationships, as well as wellbeing and life satisfaction. The initial search yielded a large amount of unrelated and irrelevant articles since the term "positive relationships" is used predominantly in different contexts than social relationships (mainly in reporting statistical relationships). This led to more targeted searches with the use of keywords such as parenting, friendship, attachment, aging, marriage, intimate relationships. More than 350 scientific papers were initially retrieved but after further careful examination, we located 35 articles that, according to the authors' judgment, addressed one or both of our research questions. All the material was organized, analyzed and is here presented in reference to our research questions.

Results
Starting from our first research question, namely, "what kind of relationships are positive in people's lives", our first observation was that the existing material described relationships all through the lifespan.
In other words, different kinds of relationships were considered positive in different life stages. Hence, it seems that positive relationships change in importance and quality as the individual develops and matures. Consequently, we divided our material according to the age group examined. Our findings were grouped under the following three age groups: (a) adolescence (ages 11 to 17), (b) adult life, and finally, (c) the elderly. Interestingly, our search did not yield any findings for the earlier stages of life such as infancy or toddler years probably because the construct of well-being is rarely if ever, examined in these contexts per se. In these early years, indices such as weight gain, body functions, or emotional regulation, are usually used as indicators for the mental and/or physical health of the child. The construct of wellbeing is used and measured initially in studies that examine school-age children and more extensively during adolescence and onwards.
During early adolescence, the child's relationships that contribute to wellbeing are relationships with parents, teachers, siblings, and peers, while in later years they are restricted to parents and peers. For the adults and the elderly, the relationships examined are predominantly marital or partnership relationships, followed by friends, and relationships with siblings and children.
Regarding our second research question, we describe below our findings organised by age group. Starting with research on adolescents (appx. ages 11 to17), it is important to note here that for this age group the adolescents' adjustment to school life is thoroughly investigated and is considered as an indicator of their wellbeing, hence, we included this line of research in our review. It has been shown that adolescents that receive support from their parents and friends are more engaged in school life, they do their homework and actively participate in the classroom, which leads to higher wellbeing. More specifically, a large-scale research has revealed that adolescents capitalize on the support they receive from parents and peers differently, with the first being beneficial in supporting their actions and behavior while the second supports their emotional engagement in school life (Estell & Perdue, 2013).
A study that examined the independent and combined support adolescents receive from parents, teachers and peers revealed that indeed all three types of support have independent and different ways in which they support adolescents' school life. It was also revealed that the quality of these relationships can significantly change the level of adolescents' adjustment in school life. Contrary to common belief that the peer group is the most influential of all three, the study showed that positive and affectionate relationships with teachers may be more or equally influential. The relationships with teachers, parents and peers (with no-antisocial behaviors) create a support network which has a motivational effect and balances the general decline of school engagement that usually takes place during this developmental stage (Wang & Eccles, 2012).
Apart from the influence of parental support in school life adjustment, parental relationships have been further examined since it is shown that they remain a protective factor for the adolescent's life and overall development. When adolescents perceive the relationship with their parents as supportive, this leads to reduced depressive symptoms; this correlation is more stable than the effect of their friendly relations and is maintained over time (Hazel et al., 2014). It has been shown that when parents promote the adolescents' autonomy, they also promote their wellbeing levels (Colibee et al., 2014;Smokowsky et al., 2014;Schiffrin et al., 2013;Van der Giessen et al., 2014).
During early adolescence (ages 10-13) the child's relationships with his/her parents contribute significantly to his/her wellbeing, as is expected, especially with regards to parenting style (Smokowski et al., 2014). Specifically, the "authoritative parenting style" positively affects child wellbeing, with the prerequisite that parental involvement does not adversely affect the children's autonomy (Raboteg-Saric & Sakic, 2014).
Using the data from a longitudinal study, Stafford, Kuh, Gale, Mishra and Richards (2015) studied parental relationships in a sample of 5,362 participants from the early adolescence, 13-15 to 60-64 years of age. They concluded that the parent-child relationship leads to higher levels of wellbeing when the relationship combines great parental care and lower parental psychological control.
With regard to peer relations, the quality of these relationships is significant and predicts the probability of adolescent involvement in dangerous behaviors. Positive peer relationships, defined as lacking peer conflict, were associated with less risky behaviors, which is an indirect indicator of well-being (Telzer et al., 2015). Positive friendly relations are generally important for easing development and better adaptation (Kornieko & Santos, 2013).
In recent years, research has turned to online friends as well as to factors that characterize communication among adolescents, such as text messaging. In particular, the number of online friends seems to be positively correlated with well-being for reasons that are not yet clear (Wang et al., 2014, while messaging seems to increase the quality of the friendly relationship (Best et al., 2015).
In adulthood, the network of friendships shows variations during the person's life (Wrzus et al, 2015) and the authors suggest that it is ultimately formed according to the similarity-attraction theory (Byrne, 1971). According to this theory, the quality of the relationship interacts with the personality of the individuals and causes a co-evolution. When the relationship is positive, friendship provides companionship and emotional proximity depending on the likeness of friends with each other.
During adulthood, conjugal or partnership relationships are those that have attracted much interest in adult life research. Marriage seems to have a lasting positive effect on happiness. Married people reported being significantly happier throughout their marriage, from 10 to 35 years, regardless of whether they were first or second marriages, compared to those who were single, divorced, or widowed. They also declared to be happier than single people (Wadsworth, 2015). Additionally, it is argued that the positive qualities of marriage are carried over to children's emotional health, hence, marriage positively influences the life conditions and the psychological wellbeing of the children that are raised (Ribar, 2015).
In general, positive marital relationships offer companionship, support, proximity and social status, and these effects were similar in the case of simple cohabitation (Amato, 2015;Musick & Bumpass, 2012). It has also been documented that for women the beneficial effects of marriage in their wellbeing deteriorate over time faster than men's. This trend is not yet fully understood; it is often attributed to women's greater awareness of the quality of the relationship that shifts over time. The author underscores that this trend may put women's mental health in a more vulnerable position (Amato, 2015).
Moving on to the study of older age, surveys in the elderly showed that although their social network is decreasing, the levels of perceived support remain stable. A positive marital relationship is the most important predictive factor of wellbeing, while other family members (e.g. siblings, children) and friendly relationships contribute to the alleviation of aging symptoms, greater sense of life satisfaction and are negatively correlated to depressive symptomatology (Antonucci et al., 2010).
Chen and Feeley (2014) examined a sample of 7,367 individuals between 50 and 108 years old. They measured the support or strain they received from four kinds of relationships: spouse/partner, children, family and friends and their levels of wellbeing. They concluded that social support from all sources can significantly increase individual wellbeing either on by itself or by the mediating effect of loneliness. It is worth noting that the data showed that the support received by the spouse/partner and friends was able to increase or decrease individual wellbeing while the other relationships i.e. children or family did not have any similar effect.
The importance of kin versus non-kin relationships in this age group had also been examined by Merz and Huxhold (2010). Using a German sample of 1,146 participants, they reported that older adults had different reactions to their kin and non-kin relationships. People who had better relationships with their family and relatives (kin) and received emotional support from them, had higher wellbeing and this trend was maintained even when people did not receive practical support from these relationships. This finding was not replicated with the non-kin relationships. However, in a later study (2,032 older adults, age 65 and older, by a German representative sample), it was shown that while interactions with family raised people's positive affect it failed to increase their overall wellbeing. On the contrary, interactions with friends led to experiencing more positive affect, less negative affect and higher levels of wellbeing, meaning that friendships in this age group may act as a protective agent for people's wellbeing. Additionally, the positive impact of friendly relationships seems to be greater for older women than for older men (Huxhold et al., 2013). Carr, Freedman, Cornman, and Schwarz (2014) examined the relationship between the quality of marital life and its contribution to subjective wellbeing on a large sample of 722 participants aged above 50. They examined the individual marriage appraisals for both spouses and they correlated them with individual wellbeing. Interestingly, the levels of individual wellbeing were influenced only by individual appraisals for the quality of marriage and were not mediated or influenced in any way by the spouses' appraisals.
Finally, in exploring how positive relationships affect wellbeing, our review located a line of research that examines this question directly on the microlevel of everyday commutation, regardless of the context in which these communications take place. More specifically, it has been shown that when people share good news with other people and the latter react actively and constructively, expressing, for example, genuine pride and enthusiasm, then the effect of the positive event increases and causes a longer-lasting and more intense effect on the wellbeing of the individual (Gable & Reis, 2010;Reis, et al., 2010). The same applies to small acts of interest or kindness, such offering as some words of encouragement, an enthusiastic answer to good news, which also may have a significant impact on personal wellbeing (Eisenberger et al., 2011;Feeney & Lemay, 2012;Kane et al., 2012).
To conclude with the presentation of our findings special mention needs to be made for the work of Feeney and Collins (2015) who are the first to offer a comprehensive theoretical model that explains the contribution of social relationships in wellbeing. They argue that human relations, in general, affect individual growth in two fundamental ways. The first, and extensively studied, has to do with the support relationships offer to the individual in moments of adversity. In these cases, relationships act as a "safe harbor" where a person can escape, protect him or herself and at the same time regroup to face the difficulty. The relationship then helps to highlight the person's strengths and the challenge to act and often helps to redefine adversity as a means of positive personal development. In this way, support through the relationship is not just a shield against stress but a place where the individual recovers and evolves.
The second way in which relationships foster wellbeing is by encouraging the individual to participate in life opportunities. In that case, the authors argue, the relationship can act as "a catalyst" by encouraging the person to explore, engage in new activities and take initiatives. Relationships also aid in identifying the opportunities for growth and flourishing and preparing for action. Within the realms of the relationship the individual designs actions and strategies, manages obstacles and, eventually, becomes more involved in the new situation.

Discussion
Despite accepting that relationships are important for our lives at all levels, little research is available regarding the kind of relationships that are positive in the course of a person's life, and even less regarding their specific characteristics and the way in which these relationships are positive and contribute to wellbeing.
This review has highlighted several interesting elements in this direction. There is a lot of evidence that relationships have a positive impact on the various developmental stages of human life from school age onwards. Parents initially and later friends affect wellbeing considerably, whereas starting from adulthood, marital and partnership relationships take the toll of relationships with the most important impact.
Although the kind of relationships varies in the course of a person's life, the positive effect of relationships remains unchanged and seems to be influenced by other variables. Throughout the life of a person, preserving his or her autonomy seems to be an important factor of well-being regardless of the type of relationship. During early adolescence, for example, the adolescent's ability to feel autonomous actually makes the relationship with the parent more beneficial. Specifically, in early adolescence (ages 10-13) "authoritative parenting style" positively affects child wellbeing, with the prerequisite that parental involvement does not adversely affect the children's autonomy (Raboteg-Saric & Sakic, 2014). This sense of autonomy results in an increase in wellbeing that continues later in adolescence (Colibee et al., 2014;Smokowsky et al., 2014;Schiffrin et al., 2013;Van der Giessen et al., 2014) and adulthood (Stafford et. al., 2015).
In adulthood, marriage is repeatedly shown to be one of the stronger predictors of wellbeing. The initial finding of this strong relationships (e.g., Lucas et al., 2003) has been replicated allowing us to postulate that marriage, despite its many challenges is beneficial for people's mental health and their wellbeing. Regarding the way in which marriage is helpful, it is demonstrated that when partners have similar emotional reactions in their communications and respond empathically to each other, the marital relationship is strong and becomes a source of emotional support (Verhofstadt et al., 2009).
In the later stages of life, people continue to benefit from their relationships even though the number of their relationships is reduced. One way of explaining the aforementioned link is by the fact that people tend to exclude detrimental relationships from their lives, resulting in fewer but of better-quality relationships. Lang (2001) suggests that when older, people tend to choose their social relationships according to their changing needs, thus keeping the ones to whom they rely the most on and letting go of the relationships that are no longer important. This process of choosing and the experience of being "eclectic" with their social ties are correlated to a higher level of subjective wellbeing.
It has been surprising that mutuality has not been thoroughly examined and most studies focus on self-reported measures and descriptions of relationships. Although this gap in research may be attributed to methodological constraints, matching participants in dyads is very laborious, we may also consider the possibility that mutuality is not defining for the quality of a relationship. It is worth mentioning that in the one study, we located (i.e. Carr et al, 2014), that examines the interaction of couples' mutual appraisals of their marriage, the results indicated that the way one spouse feels about the quality of the marriage does not influence the wellbeing of the other spouse. Thus, one could argue that mutuality is not necessarily an ingredient of a positive relationship. Yet this is a suggestion that needs further exploration.
In terms of gender, there are some indications that women are more influenced by relationships than men. Again, the data are not conclusive, but it seems that women are negatively affected by a long-term marriage, possibly when they take on the role of caregiver (Amato, 2015;Musick & Bumpass, 2012). However, they also seem to benefit more from friendly relationships at a later age (Huxhold et al., 2013).
The importance of physical presence is also an issue worth exploring, as in adolescents the number of online friends and the number of text messages correlates with their wellbeing without it being obvious for the time being how this is done and whether it concerns the relationship or in their own perceptions and beliefs.
Beyond the characteristics of people and the way they relate, relationships seem to contribute to wellbeing by sharing positive moments and events and positive response. The sharing of experience with enthusiasm and willingness to engage, as well as an attitude of interest and emotional engagement, significantly increases the impact of the positive event and enhances both the relationship and wellbeing.
It is important to note that little is known about everyday relationships or contacts that include casual communications with people that are not necessarily closely tied to each other e.g. neighbors or acquaintances from communal activities. There are some initial indications that this kind of casual everyday contact is considered valuable, positive and may also be connected to higher levels of wellbeing (Holt-Lunstad & Smith, 2012).
Finally, regarding the limitations of the present study, it is important to state that this article is not a systematic literature review on the topic of positive relationships. It constitutes an initial attempt to locate and organise research that has directly examined social relationships and their impact on wellbeing. It was the authors' choice to critically select research that they considered relevant and enlightening in understanding the function of positive relationships. We deem that further exploration is needed in order to examine the positive effect of social relationships on wellbeing. We hope that future research will further clarify and the term "positive relationships" and will operationally define it for future investigation.
In conclusion, we argue that while relationships seem to contribute to wellbeing, there is not yet an exhaustive list of ingredients that make the relationship positive. We do not yet know whether the number of relationships in our lives plays a role and whether mutuality is a prerequisite for a positive relationship or not. There is also a need to study its relationship and its contribution to wellbeing not only through its support but also as a means and opportunity to participate in new life ventures and opportunities. In the future, it is necessary to further explore the term positive relationship, which is not sufficiently defined but also to explore more thoroughly the characteristics of these relationships and how they contribute to wellbeing.