Which Type of Love Is the Strongest?

Among people with children, parental love is, on average, the strongest type of love, based on fMRI neuroimaging intensity.

Source: KonstantinChristian/Shutterstock

Why do some types of love feel stronger and more intense? A new neuroscience-based study (Rinne et al., 2024) published on August 26 in Cerebral Cortex used functional magnetic resonance imaging (fMRI) to show how different types of love activate specific brain regions at varying intensities.

For this study, researchers at Aalto University in Finland measured how six types of love recruit different brain areas at various intensities when people in an fMRI focused their attention on feelings of love for the following things:

1. Parental love (love for one's kids)
2. Romantic love (pair bonding)
3. Friends (platonic love)
4. Pets (interspecies love)
5. Nature (nonsocial love)
6. Strangers (neighborly love)

"Extending conceptually beyond interpersonal relations, we further included the category of nonhuman pets to probe the neural correlates of interspecies love and a nonsocial category of love for beautiful nature to compare the neural correlates of a frequently experienced type of nonsocial love with those of social love," the authors explain.

Neuroimaging Maps Love Inside Our Brains

The neuroimages represent a statistical average of how different types of love light up different brain regions.

Source: Pärttyli Rinne et al. 2024, Aalto University/Creative Commons (CC BY 4.0)

The fMRI neuroimages above were taken in real time and illuminate how each type of love activates slightly different brain regions depending on the object of someone's love and focused attention from moment to moment inside a functional magnetic resonance machine.

Of these six types of love, Rinne et al. found that parental love for one's child (or children) typically generated the most intense brain activity among people with kids. "In parental love, there was activation deep in the brain's reward system in the striatum area while imagining love, and this was not seen for any other kind of love," first author Pärttyli Rinne said in a news release.

Activation of the medial prefrontal cortex and precuneus observed during parental love supports empathy, theory of mind, and innate concern about a child’s well-being, highlighting the deep emotional and protective bond most parents have with their children.

That said, these findings may also provide fresh clues about the neurobiological underpinnings of maladaptive attachment styles. It's possible that a lack of brain activity in critical areas typically associated with parental love could interfere with some parents' ability to bond with their children and could make them "unloving" parents.

For example, a 2021 study found that postpartum depression is associated with altered neural connectivity between mentalizing and affective brain regions during mother-infant bonding. More research is needed to identify how a lack of brain activity in neural areas typically associated with parental love might play a role in parent-child estrangement.

Why Romantic Love Feels So Intense

On average, romantic love was a close second to parental love in terms of the intensity of neural activity in the brain's reward centers. Love rooted in romantic bonds and sexual attraction was associated with significantly stronger and more widespread activation in the brain's reward system than love for strangers or nature.

Robust neural activity in the ventral striatum suggests that romantic love is strongly linked to the brain's reward system. Passion enhances lovers' motivation to pursue goal-seeking behaviors linked to eudaimonia and pleasure. During romantic love, the anterior insula and posterior cingulate cortex process emotional and bodily awareness simultaneously, illustrating the potent combination of mental and physical connection lovers feel.

Pets Take Interspecies Love to Friendship Levels

Neuroimaging suggests that pet lovers' brains respond differently to loving a different species (e.g., dog, cat) than people who don't own pets. As might be expected, pet owners who feel deep love for their domestic animals displayed similar intensities of neural activity during brain scans when they thought about loving pets (interspecies love) as they did when thinking about loving friends (interpersonal love).

Among pet lovers, activation of the ventral striatum and caudate nucleus indicates that love for pets is gratifying and can elicit feelings of joy and attachment similar to those experienced in human relationships. The activation of the anterior cingulate cortex and medial prefrontal cortex reflects the strong emotional bond between humans and their pets. The posterior cingulate cortex activity indicates how pets are often integrated into their owners' personal narratives and sense of identity.

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In friendships, ventral striatum and caudate nucleus activation points to the rewarding aspects of social connections and shared experiences. The dorsal anterior cingulate cortex and medial prefrontal cortex are also activated by friendship. Brain areas tied to social cognition, theory of mind, and understanding others' perspectives are all key to maintaining close friendships. Activity in the posterior cingulate cortex reflects how friendships are intertwined with one's sense of identity, imagined future selves, and life history.

Strangers Don't Trigger a Bright Love Glow

As expected, feeling "neighborly love" for a stranger was the weakest type of interpersonal love. Parental, romantic, platonic, and pet lovers' love for their domestic animals all recruited reward and social cognition brain areas more intensely than the degree of love study participants felt towards strangers.

Similarly, appreciating natural beauty, a type of nonsocial love, also showed weak activation during fMRI brain scans compared to other kinds of love.

Love's Complexity Goes Beyond Brain Scans

To sum up, this study shows how the object of someone's love modulates how strongly they feel love and suggests that the strength of love someone feels is correlated with how intensely specific brain areas "light up" inside an fMRI. The strongest types of love are all associated with more robust activation in the brain's reward centers.

The researchers hope their latest (2024) research on how six types of love differentially recruit brain areas associated with reward and social cognition will help advance treatment options for people with relationship issues or attachment disorders.

In closing, the authors acknowledge some of this study's limitations. As they explain, "Love is a complex and multifaceted set of biologically grounded and culturally modified phenomena. Further cross-cultural research is still required for a better understanding of how cultural and demographic factors influence various feelings of love and their correlates in the human brain."

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