The psychology of love in romantic relationships: New research hints at its true purpose

A recent study published in the journal Human Nature provides evidence that romantic love is highly valued worldwide when people consider long-term relationships. Most people across different cultures are unwilling to commit to marriage without feeling love for their partner. Furthermore, the study reveals that the importance of love in choosing a marriage partner varies based on factors like gender, socioeconomic status, and the level of development in one’s country. These findings support the idea that love functions as a commitment mechanism, reinforcing bonds between partners and helping to maintain stable relationships.

The researchers were interested in understanding why romantic love exists and what its purpose might be. Several theories attempt to explain the phenomenon of love. One theory suggests that romantic love evolved from the attachment bonds formed between infants and caregivers, which are essential for survival and well-being. Another theory proposes that romantic love is a biological system designed to encourage couples to stay together and raise children. A related idea is that love serves as a “commitment device,” helping partners remain faithful and committed to each other, which, in turn, increases their chances of successfully raising offspring.

If romantic love indeed serves to promote commitment, then it should be a universally desired trait when people choose partners for long-term relationships, such as marriage. This is because a committed partner is more likely to provide emotional and practical support, share resources, and help raise children.

Prior research has shown that people across many different countries rated love as the most important characteristic in a long-term mate. The researchers in the current study wanted to further investigate this concept and explore whether certain groups of people might value romantic love more than others. Specifically, they wanted to test the idea that romantic love might be particularly important for those who have more to lose if their relationship ends, such as people with fewer financial resources, women (who bear the greater biological costs of having children), and individuals with more children (who require more support from a partner).

“Love is ubiquitous in modern societies, especially the types of love people experience in romantic relationships. There has been an evolutionary theory since 1988 that love serves to signal and promote commitment to a loved one. While there have been some studies that support this notion, most have relied on relatively small samples in only one country,” said study author Adam Bode, a PhD student at the Australian National University.

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“We wanted to see if there was support for this theory around the world, and if there are differences in different cultures. Marta Kowal, the lead author on this paper, is an expert on large, cross-cultural studies of love in romantic relationships, and she has access to some amazing data. One of those datasets asked a hypothetical question about the importance of being in love with a partner you choose to marry. That created the opportunity to test some hypotheses related to this theory in a really large international sample.”

The researchers collected survey data from 86,310 participants across 90 countries. The survey asked respondents how important romantic love was when considering a long-term romantic relationship. The key question was based on a classic study from 1967, which asked whether people would be willing to marry someone who had all their desired qualities except for romantic love. Responses were recorded on a scale from 0 (definitely would not marry) to 100 (definitely would marry), with higher scores indicating a lower emphasis on romantic love.

The survey also collected information about participants’ gender, socioeconomic status (based on their self-reported financial prospects), and the number of children they had. Additionally, the researchers used the Human Development Index, a measure that combines a country’s average life expectancy, education levels, and income, as an indicator of each country’s level of modernization.

The results confirmed that romantic love is highly valued across the globe, with most people expressing reluctance to enter a long-term relationship without it.

“Most people in most countries are not prepared to marry someone they haven’t fallen in love with,” Bode told PsyPost. “That should make people who desire and seek out love to feel that this is normal. The other interesting finding is that the importance of falling in love with the person you end up marrying differs according to demographics and environment.”

People with lower socioeconomic status valued romantic love more than wealthier individuals. This finding supports the idea that love plays an essential role in maintaining relationships when external resources are limited. For individuals with fewer financial means, a stable and committed romantic partnership can offer security and support, making love an important factor in their decision to commit.

Women also placed a higher value on romantic love compared to men. This aligns with evolutionary theories suggesting that women, who bear greater biological costs in reproduction, have historically been more selective in choosing partners. Because women face higher potential risks when a relationship ends, romantic love may serve as an important signal of commitment and long-term stability. This gender difference was the strongest observed effect in the study, reinforcing the idea that love plays a particularly significant role for women when evaluating long-term relationships.

The researchers also found that individuals with more children placed a greater emphasis on romantic love. Parents, especially those with multiple children, may view love as a stabilizing force that helps maintain a supportive and cooperative partnership. Raising children requires significant time, energy, and resources, and a committed, loving partner can ease the challenges of parenting. Although this effect was not as strong as the impact of socioeconomic status or gender, it suggests that love may become increasingly important as family responsibilities grow.

On a broader level, the study found that people from more developed countries placed a higher value on romantic love than those from less developed nations. This may be due to cultural influences, as modern societies tend to emphasize individual fulfillment and emotional satisfaction in relationships. In contrast, in less developed regions where economic or social factors play a larger role in marriage decisions, love may not be seen as a necessary requirement for long-term commitment.

“Not too much surprised us,” Bode said. “Our three hypotheses were supported. That being said, despite higher levels of national development being associated with a greater importance of love, lower individual-level socio-economic status was actually associated with a greater importance of love. Reconciling these two findings might require further research.”

While these findings provide strong support for the idea that love acts as a commitment mechanism, the study has some limitations. The sample was not entirely representative of all populations, as it included a higher proportion of well-educated individuals. Additionally, the researchers relied on a single question to measure the importance of love, which may not fully capture the complexity of romantic relationships. Cultural norms and attitudes toward marriage and commitment may also influence responses in ways that were not fully accounted for.

Future research could explore additional factors, such as age, religious beliefs, and societal norms around marriage and divorce, to provide a more comprehensive understanding of how love is valued across different contexts.

“Some of the authors’ areas of interest include love in romantic relationships,” Bode explained. “There are plans for further large-scale and cross cultural research using this and similar datasets, as are more targeted studies looking at specific aspects and features of romantic love. Love is a fascinating, important, and understudied area of human mating. We hope that studies like this one will promote more researchers to look into love in romantic relationships.”

The study, “Love as a Commitment Device: Evidence from a Cross-Cultural Study across 90 Countries,” was authored by Marta Kowal, Adam Bode, Karolina Koszałkowska, S. Craig Roberts, Biljana Gjoneska, David Frederick, Anna Studzinska, Dmitrii Dubrov, Dmitry Grigoryev, Toivo Aavik, Pavol Prokop, Caterina Grano, Hakan Çetinkaya, Derya Atamtürk Duyar, Roberto Baiocco, Carlota Batres, Yakhlef Belkacem, Merve Boğa, Nana Burduli, Ali R. Can, Razieh Chegeni, William J. Chopik, Yahya Don, Seda Dural, Izzet Duyar, Edgardo Etchezahar, Feten Fekih-Romdhane, Tomasz Frackowiak, Felipe E. García, Talia Gomez Yepes, Farida Guemaz, Brahim B. Hamdaoui, Mehmet Koyuncu, Miguel Landa-Blanco, Samuel Lins, Tiago Marot, Marlon Mayorga-Lascano, Moises Mebarak, Mara Morelli, Izuchukwu L. G. Ndukaihe, Mohd Sofian Omar Fauzee, Ma. Criselda Tengco Pacquing, Miriam Parise, Farid Pazhoohi, Ekaterine Pirtskhalava, Koen Ponnet, Ulf-Dietrich Reips, Marc Eric Santos Reyes, Ayşegül Şahin, Fatima Zahra Sahli, Oksana Senyk, Ognen Spasovski, Singha Tulyakul, Joaquín Ungaretti, Mona Vintila, Tatiana Volkodav, Anna Wlodarczyk, Gyesook Yoo, Benjamin Gelbart, and Piotr Sorokowski.