In psychology, a difference is often made between two types of love: passionate love and companionate love. Evolutionary theories suggest these two types of love serve different purposes, and research from psychology and biology shows they work in somewhat different ways. Both passionate and companionate love can help people feel happy in their relationships. These two types of love are also different from a third kind of love called compassionate love, which focuses on caring for others.

Passionate love is sometimes called "romantic love" in some areas of study, especially in biology, but the term "passionate love" is most commonly used in psychology. Experts in love studies do not all use the same terms. Other names for passionate love include "being in love," having a crush, obsessive love, limerence, and eros.

Companionate love is often called "attachment" or compared to strong liking, friendship love, or storge. This type of love is usually linked to the "attachment system" from attachment theory, but not all authors agree on this connection.

Passionate love

Psychologists often measure passionate love feelings using a questionnaire called the Passionate Love Scale (PLS). Elaine Hatfield and Susan Sprecher describe passionate love as a strong emotional state that includes intense feelings like joy, fulfillment, and also pain or suffering. Hatfield explains that the word "passion" originally meant suffering, as in the suffering of Christ. Passionate love is not an emotion itself but a driving force that causes different emotions depending on the situation, such as happiness when love is returned or sadness when it is not. A 2014 study of Iranian young adults found that early romantic love was linked to increased energy, positive social interactions, and better sleep, but also higher levels of depression and anxiety. The study concluded that romantic love is not always a happy time.

Passionate love is usually strongest in the early stages of a relationship, when it is new or before a relationship begins. However, in rare cases called long-term intense romantic love, strong attraction can last for many years.

In modern studies, passionate love is sometimes seen as a mix of different feelings. For example, the PLS includes questions that also measure companionate love, which led to the creation of the Infatuation and Attachment Scales (IAS) by Sandra Langeslag and others to better measure passionate and companionate love. The PLS also includes questions about obsessive feelings, which are different from intense attraction. While Hatfield originally included sexual attraction as part of passionate love, modern researchers agree that sexual and romantic attraction are separate. People can feel love without sexual desire.

The Infatuation Scale (similar to passionate love) includes questions like:
• Thinking about the person a lot and staring into space.
• Feeling nervous or shaky when near the person.
• Losing interest in food because of thoughts about the person.
• Having trouble focusing because of thinking about the person.
• Worrying about saying the wrong thing when talking to the person.
• Sweating or feeling clammy when near the person.
• Feeling tense when close to the person.
• Having trouble sleeping because of thinking about the person.
• Looking for hidden meanings in the person’s words.
• Feeling shy around the person.

Langeslag and others found that infatuation is more connected to negative emotions than attachment and often decreases once a relationship begins. People who are not in relationships tend to score higher on infatuation.

The word "infatuation" is sometimes used to describe love in a way that differs from "love," but Hatfield argues the difference is only in how people use the words. Some researchers suggest that people use "infatuation" to describe past relationships and "love" for current ones. Hatfield notes that when people say someone is "just infatuated," they may mean they do not approve of the relationship.

Passionate love includes obsessive thoughts, uncertainty, and mood changes. One study found that people in love often think about their partner for about 65% of their waking hours.

Studies by Bianca Acevedo and Arthur Aron found that the obsessive part of the PLS can be separated from the non-obsessive part. Questions about obsession include:
• Feeling unable to control thoughts about a partner.
• Finding it hard to focus on work because of thinking about a partner.
• Feeling very sad when things go wrong in a relationship.

Questions about non-obsessive love include:
• Wanting to be with a partner physically, emotionally, and mentally.
• Believing a partner is the perfect romantic partner.
• Preferring to be with a partner than anyone else.
• Feeling a strong attraction to a partner.

Acevedo and Aron found that obsessive passionate love was linked to higher happiness in short-term relationships but lower happiness in long-term ones. Another study by James Graham found that obsessive romantic feelings were connected to less happiness over time.

These researchers suggest that obsessive romantic feelings may be related to attachment styles. Attachment styles describe differences in how people think and behave in relationships, especially about feeling secure or insecure. These styles can include anxiety (worrying a partner is not attentive) and avoidance (preferring not to rely on others). Some studies suggest attachment styles form during childhood or adolescence, but others suggest they may also be influenced by genetics. People can have different attachment styles with different partners, such as an avoidant partner making a secure partner feel anxious.

Idealization, or seeing a partner in a very positive light and ignoring their flaws, is a type of positive illusion. A 1996 study found that couples who idealized each other were happier in their relationships. A brain scan study also found that couples still in love after four years showed brain activity linked to overlooking a partner’s flaws.

While Hatfield and others have linked idealization to passionate love, studies on positive illusions have looked at couples in different relationship stages, including long-term couples.

Companionate love

Companionate love is often described as being less intense than passionate love. It is more about gentle affection that grows when things are going well. Elaine Hatfield explains that companionate love is "a steady fire that burns brighter with happy experiences but can be put out by sad ones." This type of love is usually found in long-term relationships, and Hatfield highlights that having a compatible partner is important. Ellen Berscheid notes that companionate love may be essential for many relationships and can lead to a more satisfying marriage than romantic love.

Companionate love is connected to intimacy, and Hatfield says that relationships with this type of love often have these traits:

Companionate love is sometimes considered the same as storge, but James Graham argues that storge more closely matches practical friendship, which lacks qualities like intimacy and commitment that are part of companionate love.

Langeslag et al.'s Attachment Scale (similar to companionate love) includes questions about:
– Feeling that someone can be trusted.
– Being willing to share things with someone.
– Feeling lonely without someone.
– Believing someone is the right person for them.
– Thinking someone knows everything about them.
– Hoping their feelings for someone never end.
– Feeling emotionally close to someone.
– Feeling comforted by someone when upset.
– Believing someone makes them happiest.
– Including someone in future plans.

Companionate love is sometimes compared to the "attachment" described in attachment theory. John Bowlby originally described an "attachment system" as a way for infants to stay close to their caregivers. This system helps children feel safe while exploring the world, seek closeness when scared, and feel sad when separated. Some theories suggest this system is reused in adult relationships, where it takes on a new purpose.

However, companionate love is also seen as similar to strong friendship. Ellen Berscheid points out that it is unclear if all adult relationships are attachments in the way described by attachment theory. She states that the idea that romantic partners act as each other's attachment figures needs more scientific research.

Timeline

Passionate love is sometimes linked to love at first sight. However, not everyone experiences love quickly or suddenly. In one study involving Chinese and American participants, 38% fell in love quickly, and 35% fell in love slowly. In another study with Iranians, 70% fell in love slowly or very slowly.

A popular idea suggests that passionate love changes into companionate love over time in a relationship. Other explanations say that companionate love, which takes longer to develop, is also important at the start of a relationship. Sometimes, companionate love may come before passionate love. Research suggests that attachment, a type of emotional bond, takes about two years to develop. For example, one study found that people in relationships for about two years began to see their romantic partner as an attachment figure, while others still named a parent as their attachment figure.

One estimate for how long passionate love lasts is 18 months to 3 years. This comes from survey data collected by Dorothy Tennov for her 1979 book Love and Limerence. Another estimate comes from a 1999 experiment by Donatelli Marazziti and colleagues. They found differences in blood serotonin levels between people who were newly in love and others who were not. These levels returned to normal after 12 to 18 months. In rare cases, intense attraction can last much longer, as seen in the phenomenon of long-term intense romantic love. These lovers usually show less obsession than they did in the early stages.

Companionate love is believed to grow gradually as a relationship continues. However, it may decrease very slowly over many years. In the past, some people thought companionate love remained stable once it developed. However, one study of new marriages found a decline in companionate love after one year.

Causal conditions

Many theories explain why people feel love for certain people and when they feel it. Most experts agree that passionate love and companionate love work in different ways.

Companionate love usually grows when people like each other and become more familiar with one another. However, the reasons behind passionate love are more complex. Research shows that love and conflict can happen at the same time in a relationship. Passionate love, in particular, may become stronger when negative emotions are present.

Ellen Berscheid explains that companionate love follows the "pleasure-pain principle," meaning people tend to like those who make them feel good and dislike those who cause them pain. Factors that influence companionate love include similarity, familiarity, expressions of self-esteem, validation of one’s worth, physical attraction, and sharing personal information. While passionate love often comes before companionate love, Berscheid says companionate love can also help develop passionate love.

Experts disagree about how much sexual desire affects romantic love.

Passionate love is often linked to sexual desire. For example, Berscheid suggests that passionate love may result from a mix of companionate love and sexual desire. However, Lisa Diamond argues that while sexual desire is often involved, passionate love can happen without it. Diamond supports this with reports, historical examples, and an evolutionary argument that the brain systems behind romantic love evolved separately from sexual orientation. She believes time spent together and physical touch can replace sexual desire and help build romantic love between partners of any sexual orientation.

Helen Fisher says passionate love is connected to how mammals choose mates. People may have preferences that influence who they fall in love with, but Fisher explains this is different from the sex drive, even though they are related.

Berscheid notes that emotional excitement, like happy surprises, can create feelings of passion. Surprises and uncertainty are common in new relationships because partners often behave unpredictably, which can create excitement.

Fisher suggests doing exciting and new activities together to keep passion alive. In an experiment by Arthur Aron and Christina Norman, couples who did exciting tasks reported more happiness and romantic feelings than those who did boring tasks.

Elaine Hatfield says that negative or mixed emotions can increase passionate love. She explains that physical excitement and unpleasant experiences can be just as stimulating as positive ones. Hatfield cites a study where puppies who were sometimes rewarded and sometimes mistreated became more attached to their trainers. People who act predictably create little emotion, but sudden changes, like a friend becoming unkind or an enemy showing kindness, can spark interest.

Another idea is that passion grows when intimacy increases quickly. Arthur Aron and Elaine Aron suggest that passion happens when people rapidly expand their sense of self by including the qualities of their partner into their identity. These theories predict that passion may fade as relationships become more familiar and stable.

Love regulation is the process of using actions or thoughts to change how strongly someone feels romantic love. Sometimes love feelings are too strong, such as after a breakup, or too weak, such as in long-term relationships. Sandra Langeslag notes that it is a common belief that love feelings cannot be controlled, but studies show they can be managed.

For example, looking at pictures of a loved one can increase feelings of infatuation (passionate love) and attachment (companionate love).

A method called cognitive reappraisal involves focusing on positive or negative aspects of a partner, the relationship, or future possibilities:

• Negative reappraisal focuses on negative traits of a partner ("he is lazy," "she is always late"), problems in the relationship ("we argue a lot"), or future issues ("he will cheat on me"). This can reduce feelings of infatuation and attachment but may lower mood temporarily. Langeslag suggests distraction can help with this. Negative reappraisal may help people deal with heartbreak or end harmful relationships.
• Positive reappraisal focuses on positive traits of a partner ("he is kind," "she is spontaneous"), strengths in the relationship ("we enjoy spending time together"), or future hopes ("we will be happy together"). This can increase attachment and improve relationship satisfaction, which may help strengthen long-term relationships.

Love regulation does not change feelings instantly. Langeslag recommends writing down thoughts daily to create lasting changes in how love feels.

Biology

Passionate and companionate love are connected but different. They involve different parts of the brain and help with different goals. Passionate love may have developed to help people choose a partner or start a close relationship. Companionate love helps keep a relationship strong, keeps partners close, and encourages friendly actions.

Passionate love is often linked to a brain chemical called dopamine. Companionate love is often linked to a brain chemical called oxytocin, and sometimes another chemical called vasopressin or endogenous opioids.

Passionate love is sometimes compared to addiction, but there are differences. People in the early stages of romantic love may feel similar things to addicts, like strong happiness or a strong desire for their partner. However, these feelings usually fade over time, while addiction often gets worse. Helen Fisher has said that romantic love can be a "positive addiction" when it is mutual, but a "negative addiction" when it is not returned or is not appropriate.