Relationship quality describes how people think a close relationship, such as a romantic relationship, friendship, or family connection, is. It is often used the same way as terms like relationship satisfaction, relationship happiness, or relationship flourishing. In close relationships, relationship quality shows how a couple feels about their relationship overall. Simply put, it is how much people in a relationship, whether romantic or not, believe their relationship is positive or negative.

Relationship quality is usually measured by asking people to share their opinions about qualities that make up a good relationship. For example, closeness might be tested by asking questions like, "I feel close to my partner" or "I am comfortable sharing personal thoughts with my partner." These questions are answered on a scale, such as from 1 to 5, and the average score shows how close someone feels to their partner. Some tools measure only one part of relationship quality, while others look at multiple parts, like closeness and satisfaction, and combine them to create a total relationship quality score.

In the past, most research focused on romantic relationships. Recently, studies have also looked at other close relationships, such as friendships, family, and parent-child connections. Scholars sometimes disagree about which areas should be included when measuring relationship quality, even within the same type of relationship. However, relationship quality and what affects it remain important topics for researchers because strong relationships are linked to many positive outcomes, such as better mental health and stronger connections.

In romantic relationships

Early studies on romantic relationships often used two main methods to measure relationship quality. Both methods relied on people's own reports about how they felt about their relationships. The first method focused on actions that could be observed, such as how often conflicts happened, how much time couples spent together, or how often they worked to keep their relationship strong. The second method looked at how people felt inside, such as how committed, passionate, or trusting they were in the relationship. Today, many tools used to measure relationship quality focus more on the second method, aiming to identify different psychological aspects, such as satisfaction, commitment, or trust, that together describe the overall quality of a relationship.

Scholars generally agree that several key aspects contribute to relationship quality. These include satisfaction, commitment, trust, closeness, intimacy, passion, independence, and relationship flourishing.

Some of the most commonly used tools to measure relationship quality in romantic couples are:

• Quality of Marriage Index (QMI): This tool uses six questions to measure relationship quality directly. Example questions include: "My relationship with my partner is very stable," "We have a good relationship," and "I really feel like part of a team with my partner."

• Perceived Relationship Quality Components (PRQC): This tool measures multiple aspects of relationship quality, including satisfaction, commitment, intimacy, trust, passion, and love.

• Relationship Flourishing Scale (RFS): Created by Blaine J. Fowers and others, this tool focuses on how relationships grow and improve over time. It includes 12 questions that assess meaning, personal growth, sharing goals, and giving support within the relationship.

• Couple Satisfaction Index (CSI): This tool has 32 questions to measure overall relationship satisfaction. Shorter versions include 16 questions (CSI-16) and 4 questions (CSI-4). Example questions are: "Do you enjoy your partner's company?" and "How rewarding is your relationship with your partner?"

Many studies have shown that high-quality romantic relationships are linked to better physical and mental health. People in high-quality relationships are less likely to be diagnosed with or experience symptoms of conditions like generalized anxiety disorder, post-traumatic stress disorder, major depressive disorder, or bipolar disorder. People who view their relationships as high quality are usually happier, less stressed, and more satisfied with life compared to those in low-quality relationships. Research also shows that strong relationships contribute to better physical health, including higher self-reported health ratings, lower chances of death, better heart function, and faster healing of wounds.

In friendships

Friendship quality refers to how strong and positive a person's friendships are. While less studied than romantic relationships, research has explored what makes friendships high quality and how they affect mental and physical health.

Scientists do not all agree on exactly what makes a friendship high quality. However, a high-quality friendship is generally seen as one where both friends show similar levels of helping and caring actions and feel comfortable relying on each other for support. Studies often separate research on friendship quality into two groups: friendships among teenagers and friendships among adults.

A common tool used to measure friendship quality in teenagers is the Friendship Qualities Scale. This scale includes five parts: companionship, conflict, help, security, and closeness. High-quality friendships in teenagers are linked to better self-esteem, less loneliness, improved school relationships, and better ability to handle stress. One study found that 12-year-olds with high-quality best friends had better reactions to social rejection than those with lower-quality friendships. Other research shows that teenagers in strong friendships often report better mental health, including more happiness, stronger resilience, and less anxiety or sadness.

Studies on adult friendships share similarities with research on romantic relationships. Some studies use tools originally designed for romantic relationships, like the Marriage Quality index, but adapted for friendships. A widely used tool for measuring adult friendship quality is the McGill Friendship Questionnaire, created in 1999. This scale measures friendship quality based on six areas:

• Fun and excitement shared with a friend
• Help, such as emotional or practical support
• Closeness and trust in the friendship
• Feeling able to depend on a friend when needed
• Feeling more confident and valuable because of the friendship
• Feeling safe and comforted by a friend during difficult times

Later research focused on how people feel about their entire group of friends, not just one person. In 2022, Victor Kaufman from UCLA created the Friendship Network Satisfaction (FNS) Scale. This tool has two parts: closeness (feeling understood and close to friends) and socialization (spending time with friends). It measures how satisfied a person is with their overall group of friends, not just one individual.

High-quality friendships are linked to better mental health, happiness, and life satisfaction. People in strong friendships report feeling less lonely and less sad. University students with strong friendships often adjust better to college life and overall adult life.

People who feel more satisfied with their group of friends also report being happier with life, having better relationships with romantic partners and family, and experiencing better mental health.

In family relationships

Family relationship quality is measured using similar methods as romantic and friendship relationships. Many questionnaires, indexes, and other tools are used to assess children and their relationships. Some researchers study overall family quality, which is how satisfied people feel with the family as a whole. Others focus on specific family relationships, such as parent-child or sibling-sibling relationships.

One widely used tool to measure overall family quality is the Family Assessment Measure (FAM), created in 1983 by Skinner, Steinhauer, and Santa-Barbara. It has three parts that all family members complete.

• A General Scale that looks at how well the family functions as a group.
• A Dyadic Relationships Scale that examines relationships between specific family members, such as between a parent and child or between siblings.
• A Self-Rating Scale that lets individuals rate how well they function within the family.

Strong family relationships are linked to better mental health for family members. People with good family relationships often feel less stressed, are more resilient, have higher self-esteem, and are more satisfied with life.

Measuring parent-child relationship quality is different because children and parents answer different questions. This is unlike measures for romantic, friendship, or sibling relationships, where both people in the relationship answer the same questions. The term "parent" here includes any primary caregiver, such as a guardian or foster parent.

While there is no single agreed-upon way to measure parent-child relationship quality, it is often tied to how much support is given and received, and how that affects emotions.

Examples of tools used to measure parent-child relationship quality include:

• Parent-Child Relationship Questionnaire (PCRQ): This tool checks five areas: warmth, personal connection, discipline, power, and possessiveness.
• Parent-Child Relationship Inventory (PCRI): This tool checks six areas: parental support, satisfaction with parenting, involvement, communication, setting limits, and allowing independence.
• Parent-Child Interaction Questionnaire—revised (PACHIQ-R): This tool has separate versions for children and parents. The child version has 25 questions, and the parent version has 21 questions. Both focus on how conflicts are resolved and how accepted each person feels.

Good parent-child relationships are linked to positive outcomes for both parents and children. Many studies show that parents with strong relationships with their children report higher happiness, well-being, and life satisfaction.

Poor parent-child relationships are linked to negative health effects for children, such as unhealthy eating habits, higher chances of mental health issues, and problems with hormone production like oxytocin and cortisol. These effects can continue into adulthood.

Strong parent-child relationships help children succeed in future relationships, do better in school, and have better mental and social health in college.

While there is no universal agreement on how to measure sibling relationship quality, common factors include warmth, conflict, and how parents treat siblings differently. Warmth refers to positive aspects like closeness and friendship. Unequal treatment by parents can harm sibling relationships.

Tools used to measure sibling relationship quality include:

• Sibling Relationship Questionnaire (SRQ): This tool checks warmth, power, conflict, and rivalry.
• Sibling Relationship Inventory (SRI): This tool checks affection, hostility, and rivalry.

Poor sibling relationships are linked to more conflict, higher chances of depression, and greater risks of drug use. Strong sibling relationships are linked to better social skills, fewer problems in adolescence, fewer depressive symptoms after stress, and better mental health overall.