Adam Bode

Romantic love lacks a mechanistic, testable evolutionary account. Prior work notes parallels with mother–infant bonding but leaves the genetic architecture and falsifiable predictions unspecified. We argue that romantic love evolved not through the evolution of new “love genes,” but by altering the regulation of existing genes: changing when, where, and under what physiological conditions these genes are active. This regulatory co-option framework generates several falsifiable predictions: (1) a shared genetic basis between maternal bonding and romantic love, (2) the involvement of non-coding, regulatory DNA regions in the brain, (3) a largely shared genetic architecture between the sexes, with differences in gene expression, and (4) genetic signals localized to specific brain circuits. We outline specific genomic and statistical methods to test these predictions, establishing clear criteria that would support or refute our hypothesis. This work shifts the study of romantic love’s evolution from analogy to a program of empirical inquiry and hopes to shed light on how social monogamy entered the Homo sapiens lineage. Key challenges include the lack of high quality meta-analytic fMRI evidence of romantic love and the scarcity of detailed data from relevant human brain circuits.

Obsessive thinking about a loved one (i.e., constant, involuntary, repetitive thoughts about the loved one) is a defining feature of romantic love yet remains markedly under-researched. This article provides the first review of obsessive thinking about a loved one in romantic love, organising the disparate literature using an "Eight Perspectives" approach spanning evolutionary history, evolutionary functions, development, mechanisms, ecology, cognitions, emotions, and behaviour. We argue that obsessive thinking about a loved one likely emerged by co-opting mother-infant bonding circuitry, appears across cultures and across the lifespan, and may have evolved to promote proximity-seeking and sustained orientation toward a loved one. Contrary to long-standing claims, the mechanisms underlying obsessive thinking in romantic love are unlikely to be shared with obsessive-compulsive disorder. People who are in love think about their loved one for approximately 50% of their waking hours, and this thinking is associated with romantic (but not companionate) love, distraction, proximity-seeking behaviour, and analgesia. Whether such thinking is experienced as bothersome or enjoyable depends less on its frequency than on companionate love and reciprocation. We conclude by identifying priorities for future research across all eight perspectives.

Tinbergen's Four Questions is a widely used organizing framework for describing animal behavior that has also been applied to complex human psychobehavioral phenomena. However, it can be extended in several useful ways, making it a more comprehensive framework for the human social and behavioral sciences. To this end, we propose an Eight Perspectives framework that extends Tinbergen's Four Questions by specifying the placement and roles of ecology, emotions, cognitions, and behavior in a broader framework. The framework is designed to be useful, simple, and flexible. We demonstrate its application using the example of physical appearance enhancement, and show that it organizes findings in an easily interpretable manner, identifies gaps in knowledge, and invites collaboration across biology, ecology, psychology, and behavioral science.

Love is a near-universal human experience. However, while it transcends cultural boundaries, its intensity varies significantly across individuals and societies. We hypothesize that this variability is partly driven by socio-cultural factors, particularly individualism—a cultural orientation prioritizing personal goals over group interests. As individualism continues to rise globally, its implications for romantic relationships remain underexplored. Here, we address this by examining the link between individualism and love in two large-scale cross-cultural studies. In Study 1, we collected data from a convenience sample of 61,067 partnered individuals from 81 countries. In Study 2, we selected nationally representative samples from 50 countries, with controlled distributions of gender, age, and residential area (N = 6,620). The results were consistent across both studies—as individualism increased, both men and women reported lower levels of experienced love. In Study 2, individualism was additionally linked to a lower expressed desire for love, suggesting that individualism may erode the perceived importance of love. As people become increasingly individualistic, our findings provoke questions about the future of love. They also carry implications for societal challenges such as rising divorce rates, fertility issues, and depression—all of which have been linked to unfulfilled or unhappy love.

Tinbergen’s Four Questions is a widely used organizing framework for describing animal behavior that has also been applied to complex human psychobehavioral phenomena. However, it can be extended in several useful ways, making it a more comprehensive framework for the human social and behavioral sciences. To this end, we propose an Eight Perspectives approach that extends Tinbergen’s Four Questions by specifying the placement and roles of ecology, emotions, cognitions, and behavior in a broader framework. The approach is designed to be useful, simple, and flexible. We demonstrate its application using the example of physical appearance enhancement, and show that it organizes findings in an easily interpretable manner, identifies gaps in knowledge, and invites collaboration across biology, ecology, psychology, and behavioral science.

In collectivistic cultures, marriage represents not merely a union between two individuals but a merging of two-family systems, with extended family relationships shaping marital quality and stability. The present study developed and validated the Relational Embeddedness Scale (RES), a measure assessing family embeddedness as experienced by married couples in collectivistic cultures. In a sample of 957 married individuals in India, exploratory factor analysis in a random split half (n = 455) revealed a unidimensional structure (eigenvalue = 15.25) accounting for 49.2% of variance, with the second factor explaining only 5.3% of variance, which was subsequently confirmed through confirmatory factor analysis in the holdout sample (n = 502; robust CFI = .920, RMSEA = .049). The final 31-item scale demonstrated excellent internal consistency (α = .97) across genders, strong convergent validity with relationship satisfaction (r = .61, p < .001), and good discriminant validity from social desirability (r = .06, ns; attenuation-corrected r = .09). Hierarchical regression confirmed incremental validity, with the RES accounting for 36.0% additional variance in relationship satisfaction beyond social desirability (β = .60, p < .001). Men reported higher levels of family embeddedness (d = 0.17) and relationship satisfaction (d = 0.24) than women, although the RES-satisfaction association did not differ significantly by gender. The unidimensional structure likely reflects holistic cultural cognition in collectivistic contexts. The RES provides a reliable and valid instrument for assessing family-embedded marital processes and offers an avenue for research on how extended family systems contribute to couple functioning across cultures.

A popular saying asserts that love is blind and lovers view each other through rose-tinted glasses. We examined whether lovers recognize their partners' flaws and whether reflecting on these imperfections affects love intensity. We recruited 844 partnered individuals and randomly assigned them to a flaw recognition condition, where they described their partner's shortcomings, or to a passive control condition without such additional tasks. Frequentist comparisons revealed no significant group differences in experiences of intimacy, passion, and commitment, and Bayesian tests provided strong evidence supporting the null hypothesis. However, qualitative analyses showed that participants who reported severe transgressions, particularly infidelity or aggression, reported significantly lower love intensity. These results indicate that although lovers-even in early relationship stages often presumed to be wearing rose-tinted glasses-can typically acknowledge their partners' imperfections without their feelings weakening, love may be undermined once transgressions exceed a critical threshold. These findings can be interpreted within the love as a commitment device perspective, which posits that love serves to maintain bonds even when partners and relationships are imperfect and they also fit evolutionary accounts predicting that transgressions which threaten reproductive success (infidelity) or survival and bodily integrity (aggression) are particularly likely to erode romantic love.

There is a big problem in psychology and related disciplines related to the inconsistent use of the terminology of love in romantic relationships. The biggest problem is the use of the term "romantic love." On the one hand, a majority of researchers use the term to describe the motivational state that commonly occurs in the early stages of romantic relationships characterized by particularly intense cognitions, emotions, and behaviors (narrow sense of the term; e.g., Bode & Kushnick, 2021). This aligns with the concept of "passionate love" promoted and used by Elain Hatfield and some others (e.g., (Hatfield & Rapson, 1993). On the other hand, some researchers use the term to refer to any love that usually occurs in a romantic relationship, whether it be that state I described, or the less intense love associated with feeling of companionship that characterizes long-term romantic relationships such as marriages (broad sense of the term; (Marta Kowal et al., 2025). This dual use of the term leads to bad science as a result of misunderstanding, wasting of time and resources, and false beliefs about love in romantic relationships. There is a convention that the term "romantic love" is used in the narrow sense in the evolutionary social and behavioral science of love that should be adhered to. I am writing this opinion to lay out this convention and to advocate for researchers in the evolutionary social and behavioral sciences to follow this convention. In essence, I argue that the term "romantic love" should be used in the narrow sense, which is in line with convention in the evolutionary social and behavioral sciences (e.g., Bode, Kavanagh, & Kowal, 2025), the Englishlanguage definition (Collins, 2025), the American Psychological Association definition (American Psychological Association, 2025), the general conceptualization in the Triangular Theory of Love (Sternberg, 1986), and the convention in biopsychology (Bode & Kowal, 2023). The original classification system used to describe love in romantic relationships was formulated by Elaine Hatfield and her co-authors (e.g., (Berscheid & Walster, 1969;Hatfield & Rapson, 1993;Hatfield & Walster, 1985;Walster & Walster, 1978). They distinguished "passionate love" and "companionate love." Passionate love equates to the state of love commonly associated with the earlier stages of a romantic relationship and particularly strong cognitions, emotions, and behaviors. Companionate love equates to the less intense love felt between individuals in longer-term romantic relationships, such as married couples. The question at hand is whether "romantic love" refers to passionate love or both passionate and companionate love.Problems with methodology is the prototypical negative outcome when it comes to dual use of the term "romantic love." Not only does it mean that researchers have wasted time and resources, but it creates the false impression in the literature that we know what is either not known or is incorrect. Two recent papers spring to mind that provide good examples of bad science resulting from methodological errors. The first uses the term romantic love in a very broad sense. Han and colleagues (Han et al., 2024) undertook a bibliographic analysis of the scientific literature to describe the landscape of what they call "romantic love." In their search terms, they extended the meaning of romantic love so much as to include a search field for "romantic relationship." This probably resulted from a lack of awareness that the term "romantic love" has a precise meaning, and the authors in turn conflated related concepts associated with romantic relationships. This in effect meant that the analysis considered all studies over the past ten years that had investigated romantic relationships, and as a result, the findings are not useful in describing the literature on love in romantic relationships. This is problematic because it creates the false impression that there is a sizeable literature on love in romantic relationships and falsely heralds establishedheralds romantic relationship researchers as leaders in the field of romantic love.A second recent study (Yang, Wang, Shi, & Zou, 2024) purported to test a theory that the mechanisms associated with romantic love are similar to those involved in addiction by undertaking a meta-analysis of fMRI studies of romantic love and addiction. The theory has always been based upon a narrow definition of the term "romantic love" (see (A. Bode & Kushnick, 2021;H. E. Fisher, Xu, Aron, & Brown, 2016;Wang et al., 2020;Zou, Song, Zhang, & Zhang, 2016). Yang and colleagues (Yang et al., 2024) introduce the theory correctly, drawing on a definition of romantic love that aligns with the narrow sense. However, when it came to the selection of fMRI studies, they included not only fMRI studies of people experiencing "romantic love" -in the early stages of a romantic relationships -but also studies of people in romantic relationships for many years or even decades. This error may have resulted because the authors conducting the study were only superficially familiar with the biopsychological literature on romantic love -one field where the use of the term is notoriously consistent -or the theory. This does not excuse the fact, however, that the corresponding author was a guest editor for a special issue in this Journal on the specific theory they were testing (Zhang, Zou, & Fallgatter, 2016) and was therefore aware of the meaning of "romantic love" in the biopsychology literature. The authors concluded that there were few similarities between romantic love and addiction. However, as is clear, this study failed to appropriately test the hypothesis. This is problematic because it creates the perception that the similarities between romantic love and addiction are minimal, despite this not having been tested appropriately. I note that after this that article was published, I submitted a letter to the editor at...

Purpose of Review: The purpose of this review was to summarize the evidence about the association between romantic love and sexual frequency. We outlined what has historically been thought about romantic love and sexual frequency as well as the latest theoretical and empirical contributions to this area of research. Recent Findings: There have been three published articles that consider sexual frequency in a sample of participants experiencing romantic love. All are drawn from the same international sample: the Romantic Love Survey 2022. A number of publicly available studies not yet published also exist using this sample. Summary: It appears that young adults in love report having sex 3.5 times per week on average, but there was substantial variation in sexual frequency in this sample. This is meaningfully higher than sexual frequency found in the married/cohabiting American population.