Research on children’s and adolescents’ happiness has increased in recent years [1] due to the association between happiness and improved physical and mental health ^[2][3][2,3]. HFor the present systematic review, happiness was conceptualized as a relatively stable, positive, and affective trait ^[4][5][4,5], with an emphasis on subjective well-being and general life satisfaction ^[2][6][7][2,6,7]. Previous studies ^[8][9][8,9] have suggested that family emotional bonds and positive relationships are primary sources of children’s happiness. Indeed, dimensions of family functioning have been shown to significantly predict children’s happiness, beyond the influence of peer and school settings [10]. However, to there h best of our knowledge, there has been no systematic review of the relation between children’s happiness and family functioning. Thus, the present systematic literature review aimed to understand the associations between children’s and adolescents’ happiness and dimensions of family functioning.

Happiness is comprised of an affective and a cognitive component ^[6][11][6,11]: (a) the affective component involves high levels of pleasant emotions (e.g., joy, interest, excitement, confidence, readiness) and low levels of negative emotions (e.g., anger, fear, sadness, guilt, contempt, disgust) [12]; (b) the cognitive component represents a global assessment of quality of life, indicating the degree to which one’s essential needs, goals, and desires are satisfied [13]. These judgments are usually understood to describe overall life satisfaction, or satisfaction within a specific domain (e.g., work, family life, social life, school).

Previous studies have suggested that healthy family functioning is associated with children’s and adolescents’ happiness [14]. Since the 1980s, the Circumplex model [15] and the McMaster Model of Family Functioning (MMFF) [16] have promoted a new vision of the family as an open system in interaction with the environment. However, there is no single definition of family functioning in the literature. Regardless of the differing compositions of modern families, family functioning refers to effective emotional bonding between family members, the use of family rules, family communication, and the management of external events [17]. Thus, family functioning describes the dynamic interactions within a family unit and how a family fulfills its functions [18], referring to the ways in which family members interact and work together to achieve common goals and outcomes ^[19][20][19,20]. Various factors may influence family functioning, including family structure, socioeconomic status, life events, family relationships, and the evolutive stages of the family ^[19][21][22][19,21,22]. Although family functioning is a complex phenomenon that can be assessed in various ways [23], it generally refers to the quality of family life at a systemic level, emphasizing wellness, competence, strengths, and weaknesses [24].

Previous studies have reported that positive family functioning is associated with children’s and adolescents’ happiness ^[25][26][27][25,26,27]. In particular, research has found that family connectedness promotes well-being and parental support directly contributes to children’s happiness [28]. Furthermore, the quality of family relationships has been shown to be more important to students’ happiness than the peer group, school, or community [29].

Family cohesion and adaptability have been found to be linearly correlated with family functioning (i.e., family communication and satisfaction) [15]. Effective communication is a central feature of high family functioning [30], and research has shown that when parent–adolescent communication is good, the family is closer, more loving, and more flexible in solving problems [31]. Indeed, when defining their perceptions of well-being, adolescents frequently refer to good relationships and pleasant moments spent with family members [32].

As conflict tends to generate negative emotions, high-conflict families have been found to be associated with lower levels of happiness and life satisfaction [33]. On the other hand, family satisfaction, defined as the extent to which individuals feel satisfied with the level of perceived support from family members [34], has been shown to be associated with increased happiness and overall life satisfaction in children and adolescents ^{[35][36][37][38]}[35,36,37,38]. Other studies have confirmed that a dysfunctional family relationship (e.g., low-income, family coherence, family conflict) is a risk factor for children’s and adolescents’ happiness ^[32][39][32,39].

3. Family Dimensions Predicting Happiness

Regarding the first theme (n = 91), family dimensions (i.e., cohesion and communication) were found to strongly predict children’s and adolescents’ levels of happiness. Three interconnected subdimensions characterized this theme: family cohesion and adaptability, family satisfaction and communication, and family conflict.

3.1. Family Cohesion and Adaptability

In the selected studies (n = 21), family cohesion—reflecting the strength of the family bond—was positively correlated with both the affective (i.e., positive affect and emotions) and the cognitive components (i.e., life satisfaction) of children’s and adolescents’ happiness ^{[40][41][42][43]}[77,110,111,112]. Adolescents from families with higher cohesion reported a more positive mood and a higher level of happiness ^[42][44][111,113]. The affective component of happiness was positively correlated with family cohesion and closeness ^[25][45][25,114]. Feeling close to family members, doing things with family members, and sharing interests and hobbies with family members were also associated with happiness, especially in boys [25]. Children’s and adolescents’ happiness was positively correlated with family cohesion and intimacy ^{[7][28][46][47][48][49][50][51][52]}[7,28,44,115,116,117,118,119,120]. Therefore, children who perceived a less cohesive atmosphere at home reported lower life satisfaction and higher negative affect ^[53][121], which precipitated negative thoughts towards people and events (i.e., hostility). Therefore, increased life satisfaction and low negative affect might help children to cope with adverse events ^[42][111]. In addition, Song et al. (2018) ^[46][44] found that self-esteem mediated the relationship between family cohesion and life satisfaction. Happiness had a significantly positive correlation with family adaptability [20]—defined as the quality and expression of leadership and organization, role relationships, and rules and negotiations within the family ^[54][95]—from the perspectives of both children and parents [27]. Again, adolescents’ perceptions of family flexibility were positively associated with their happiness ^[55][56][122,123]. Although most studies reported that cohesion and flexibility were correlated with higher levels of happiness in children, Verrastro et al. (2020) [27] found that family variables were not significantly predictive of children’s happiness.

3.2. Family Conflict

The examined studies highlighted that parent–child conflict (n = 17) strongly negatively predicted children’s and adolescents’ positive affect ^[40][57][58][77,124,125] and perceived happiness ^[59][126]. Adolescents felt less happy and satisfied on days of intense conflict with parents ^[44][113], and adequate parental warmth moderated and decreased the negative effect on children’s happiness and well-being ^[57][124]. Furthermore, parent–adolescent conflict was associated with low life satisfaction of children and adolescents ^{[33][45][60][61][62][63][64][65]}[33,46,89,114,127,128,129,130], from the perspectives of both parents and children ^[66][131]. Even in late adolescence, happiness negatively correlated with family conflict before college ^[67][132]. Family conflict directly affected emotional happiness (i.e., life satisfaction and positive emotions) ^[40][62][68][77,127,133] during late adolescence. Indeed, one study found that satisfaction with life buffered the harmful effects of family conflict among undergraduate students ^[67][132]. However, other studies did not reveal a statistically-significant correlation between children’s happiness and parent–child conflict ^[33][69][33,134]. Adolescent gender moderated between- and within-family (i.e., daily cohesion and conflict) effects on mood, and the interaction between daily conflict and adolescent gender was significantly correlated with positive mood. One study found that, relative to girls, boys reported significantly lower levels of happiness in the context of family conflict ^[44][113]. However, another study found no gender differences among adolescents in the association between parent–adolescent conflict and adolescent psychological well-being ^[64][129].

3.3. Family Communication and Satisfaction

In the selected studies (n = 13), mother–adolescent and father–adolescent communication were positively associated with both the affective component (i.e., positive affect) and the cognitive component (i.e., life satisfaction) of adolescents’ happiness ^[30][70][30,135]. Children’s happiness and positive affect positively correlated with family communication [25], from both the children’s and parents’ perspectives [27]. Therefore, having family members who expressed their opinions and talked about their feelings was associated with positive affect [25]. Children’s and adolescents’ life satisfaction ^[20][71][72][20,136,137] and emotional well-being (i.e., happiness, positive affect, and life satisfaction) [30] correlated positively with family communication. Specifically, adolescents’ life satisfaction was positively associated with communicative openness with their father and mother ^[73][138] and negatively with offensive and avoidant communication with their parents ^[45][74][75][114,139,140]. Some research reported that positive (i.e., accessible, comprehensive, and satisfying) family communication significantly predicted life satisfaction ^[73][76][138,141]. Verrastro et al. (2020) [27] found an interaction between children’s gender and family communication, suggesting that, among female participants, having a family that practiced good communication was more strongly associated with higher levels of happiness. Moreover, studies found positive correlations between family satisfaction (n = 47) and happiness ^[77][78][79][142,143,144], identifying satisfaction with family life as the strongest predictor of overall life satisfaction, from childhood to adolescence ^{[3][29][35][80][81][82]}[3,29,35,42,145,146]. In particular, family satisfaction correlated positively with both the affective component (i.e., positive affect and positive emotions) and the cognitive component (i.e., life satisfaction) of happiness ^{[36][37][83][84][85][86][87]}[36,37,71,147,148,149,150]. Furthermore, family life satisfaction was positively associated with children’s positive affect ^{[85][88][89][90]}[148,151,152,153] and happiness ^[38][59][38,126], from the perspectives of both children ^{[1][91][92][93][94][95][96][97][98][99][100][101][102][103][104]}[1,154,155,156,157,158,159,160,161,162,163,164,165,166,167] and parents ^{[27][105][106][107]}[27,73,168,169]. However, one study reported a non-significant positive correlation between happiness and family satisfaction [38]. The relation between family satisfaction and life satisfaction may be bidirectional. Indeed, one study showed that positive affect predicted high school students’ satisfaction with family life ^[88][151]. On the other hand, other studies identified family satisfaction as a significant predictor of life satisfaction ^{[108][109][110][111]}[170,171,172,173]. For instance, some authors ^[36][86][36,149] found that high satisfaction with family life was related to a greater frequency and intensity of affective experiences of love, affection, joy, and happiness ^[112][174].

3.4. Global Family Functioning, Environmental Variables, and Happiness

The impact of global family functioning and family environmental variables (i.e., family relationships and family dynamics) on happiness was supported by a large number of studies (n = 39). Most articles specifically discussed the impact of dysfunctional family functioning on happiness, from both the parents’ and children’s perspectives. Many studies showed that adequate and adaptive family functioning correlated positively with higher levels of happiness ^{[18][24][69][71][112][113][114][115][116][117][118]}[18,24,134,136,174,179,180,181,182,183,184], considering both affective and cognitive components ^{[22][119][120]}[22,43,185]. Furthermore, some studies showed that family environment and happiness correlated with adolescents’ gender and age ^{[60][115][121]}[46,181,186]. Only one study found no significant relation between family functioning and adolescents’ happiness ^[122][187]. Children’s and adolescents’ global happiness correlated positively with family relationships ^{[12][123][124][125][126][127][128][129][130][131][132][133][134]}[12,90,91,188,189,190,191,192,193,194,195,196,197]. Positive relationships within the family strongly predicted increased subjective happiness ^{[110][135][136]}[172,198,199] and low depressive symptoms. Children who reported more daily activities with family members reported higher levels of happiness, regardless of the type of activity (e.g., talking, playing, learning together). Studies also indicated that adolescents’ perceptions of high mutuality and stability and a lack of severe problems in the family predicted their global satisfaction ^[1][137][1,200]. Studies further suggested that perceived good relationships in the family helped adolescents to develop feelings of freedom, love, and happiness ^{[110][131][135][136]}[172,194,198,199].

Sociodemographic Variables: Age, Gender, and Socioeconomic Status

Sociodemographic variables (e.g., age, gender, socioeconomic status) represent a subtheme of environmental factors associated with happiness (n = 21). The well-being of children and adolescents primarily depended on the closeness of their relationships with family members and, particularly, their parents. Children reported more satisfaction with their family relationships ^[135][198] relative to adolescents ^[82][119][43,146]. However, one study found no age or gender differences in the interaction between life satisfaction and family functioning ^[128][191]. Young people who perceived a higher quality parent–child relationship had greater and more stable life satisfaction from middle (i.e., aged 14–16 years) to late adolescence (i.e., aged 17–18 years) ^[134][197]. The negative correlation between family functioning and life satisfaction was affected by gender differences. Girls perceived less familial dysfunction relative to boys ^[60][46]. One study found that family satisfaction was the only significant predictor of girls’ life satisfaction [37]. Another study showed that boys with high overall satisfaction reported high stability and reciprocity and fewer problems in the family ^[137][200]. However, other studies found no gender differences in the association between these variables ^{[71][113][138]}[136,179,201]. Only one study found no correlation between family functioning and the life satisfaction of adolescent boys from low-income families ^[139][202]. Shek (1998) ^[61][89] showed that adolescents’ life satisfaction correlated with the perceived family atmosphere (i.e., family happiness and family interactions), parent–adolescent relationship, and adolescent–parent communication at both data collection points (i.e., one year apart), regardless of gender. Thus, for both boys and girls, greater life satisfaction was associated with a higher level of perceived happiness in the family and more frequent positive conversations within the family. Some studies revealed that adolescents with a more positive family environment displayed greater happiness and life satisfaction ^{[61][132][133]}[89,195,196]. Other studies revealed that the link between family functioning and life satisfaction was significantly stronger among adolescent girls, compared to adolescent boys ^[24][114][24,180]. Concerning socioeconomic status, Shek (2002) ^[140][177] showed that family functioning was more strongly related to adolescent adaptation among economically disadvantaged adolescents relative to non-economically disadvantaged adolescents. This suggests that family functioning may be associated with better adaptation in high-risk adolescents ^[22][98][22,161]. One study found that satisfaction with family functioning predicted the happiness of rural-urban migrant children—a subgroup with worse self-rated family financial situations ^[141][203].