In a new two-part study published in Behavioral Sciences, researchers have unveiled a significant link between the brain’s reward system and the intensity of romantic love. By developing and utilizing a new scale, they have shown that the way our brains respond to rewards and motivation is closely connected to how deeply we experience romantic feelings.
The study paves the way for a deeper understanding of romantic love from a biological perspective. It suggests that the intensity of our romantic feelings may be partly driven by the Behavioral Activation System — the same internal system that motivates us towards rewards and goals.
“The average person should take away two main things from our study,” said study author Adam Bode, a PhD student in biological anthropology at Australian National University. “First, when we fall in love, information about our loved one takes on a special meaning, is treated differently, and as a result, the rest of our brain reacts differently to that information. Second, romantic love, despite being known for its strong emotions and thoughts, is ultimately about behavior. The emotions and conditions we experience in romantic love are there to affect behavior and determine how we act with our loved ones.”
The Behavioral Activation System is believed to be connected to the brain’s dopaminergic systems and is associated with responses to rewards and motivation. It influences behaviors and emotions and is thought to be linked with mania-like symptoms such as high energy and exploration. When the system is activated, it propels us towards actions that are expected to bring positive outcomes.
Romantic love, a topic of endless fascination and complexity, has been explored through various lenses – social, psychological, and biological. However, its biological underpinnings, particularly how our internal motivational systems like the Behavioral Activation System contribute to it, have remained relatively uncharted territory. Researchers embarked on this study to fill this gap. They were curious about whether the Behavioral Activation System also played a role in shaping the intensity and expression of romantic love.
“A number of studies have identified similarities between romantic love and hypomania, primarily as they relate to elevated mood,” Bode explained. “The Behavioral Activation System plays a role in mania, so we wondered if the Behavioral Activation System might also play a role in romantic love. We figured out a way of measuring this (although imperfectly), and the findings suggests that our suspicion was correct, the Behavioral Activation System probably does play a role in romantic love.”
In the first part of the study, 1,556 English-speaking young adults who self-identified as being in love were involved. The researchers’ goal was to develop and validate a new tool: the Behavioral Activation System Sensitivity to a Loved One (BAS-SLO) Scale.
This tool was adapted from the existing Behavioral Activation System Scale, but with a twist – it was tailored to measure how the Behavioral Activation System responds specifically in the context of a romantic partner. Participants responded to questions that gauged their reactions and feelings towards their loved ones (e.g., “I go out of my way to maintain my relationship with my partner”).
In addition, they completed the Passionate Love Scale—30, a widely used measure that assesses the cognitive, emotional, and behavioral aspects of romantic love.
The researchers used a statistical method called confirmatory factor analysis to ensure the new scale was reliable and measured what it intended to. They tested different versions of the scale and found that an 11-item model was the most suitable.
This model encompassed dimensions of reward responsiveness, drive, and fun-seeking in relation to a romantic partner. The new scale showed good reliability and was consistent with the Passionate Love Scale, indicating it was a valid tool for measuring Behavioral Activation System in the context of romantic love.
Building on the first study, the second part involved a subset of 812 participants from the original group. These individuals were in the early stages of romantic love (less than two years) and had high scores on the Passionate Love Scale.
Here, the goal was to see if the BAS-SLO scores correlated with the intensity of romantic love. The researchers controlled for factors like gender, length of the romantic relationship, and the degree of obsessive thinking about the loved one.
The researchers found that the BAS-SLO Scale significantly predicted the intensity of romantic love, accounting for additional variance in PLS-30 scores beyond the control variables. This indicated that higher sensitivity in the Behavioral Activation System towards a romantic partner was linked to stronger feelings of romantic love. Crucially, each aspect of the BAS-SLO (reward responsiveness, drive, fun-seeking) contributed significantly to this correlation.
“The association between the Behavioral Activations System Sensitivity to a Loved One (BAS-SLO) scale and the intensity of romantic love was substantial,” Bode told PsyPost. “BAS-SLO Scale scores explained almost 9% of the variance in the intensity of romantic love — that’s a lot for a single biopsychological system.”
While the study offers new insights, it’s important to recognize its limitations. “There are two caveats,” Bode said. “The second analysis in our study used the same sample as the BAS-SLO Scale was validated in, so the results need to be replicated in a different sample. Also, we didn’t control for or take into account the normal functioning of the Behavioral Activation System. This is probably necessary to get a proper understanding of the role of the Behavioral Activation System in romantic love.”
Despite these caveats, the new findings suggest a direct link between the way our motivational system responds to a romantic partner and the intensity of romantic love we experience. The Behavioral Activation System, traditionally associated with goal-directed behavior and reward response, appears to extend its influence to the domain of romantic relationships, shaping how passionately we feel about our partners.
“Now that we know the Behavioral Activation System is involved in romantic love, there are a few lines of research we are interested in,” Bode told PsyPost. “The first is to get a better understanding of the role the Behavioral Activation plays in romantic love. That would include understanding sensitivity to a loved one, but also general sensitivity, their association with elevated mood, and the specific cognitions, emotions, and behaviors the Behavioral Activation System might cause.”
“A second line of inquiry is to develop a means of measuring Behavioral Inhibition System Sensitivity to a Loved one. The Behavioral Inhibition System essentially does the reverse of the Behavioral Activation System, and inhibits behavior. We suspect that the Behavioral inhibition system also plays a role in romantic love. Finally, we would be really keen to use the BAS-SLO Scale in neuroimaging research. It would be great to identify the neural structures associated with Behavioral Activation System sensitivity to a loved one and how this plays a role in romantic love. If there are any neuroscientists interested in doing this sort of research, please get in touch.”
“Romantic love is a rewarding and fascinating area of study,” Bode added. “There are substantial gaps in the literature and lots of low hanging fruit to be harvested. My supervisor, Phil Kavanagh from the University of Canberra and the University of South Australia, and I are the only people in the world studying romantic love using an evolutionary perspective. It’s providing great insights into not only the functions and evolutionary history of romantic love, but also its mechanisms.”
The study, “Romantic Love and Behavioral Activation System Sensitivity to a Loved One“, was authored by Adam Bode and Phillip S. Kavanagh.
