We follow a biopsychosocial approach almost by necessity in discussing love, though it’s possible to rely on Gilbert and Sullivan. It isn’t that emotions have three levels that must be addressed—biological, cognitive, behavioral—because love isn’t just an emotion. Rather, we apply the same term to phenomena that are organized differently at different levels.
That is to say that love isn’t a single phenomenon but a group of responses. Many investigators include an early flirting/proceptive/attraction phase driven by genital stimulation and hormones. In the 1960s, Walster (now Hatfield), Berscheid differentiated this early, passionate phase of love from a later, companionate phase that was less physical. Later a third phase was distinguished from the other two and those stages came to be seen as independent of each other. A little later, Sternberg invented a triangular theory of love that illustrated the styles of love that its phases might generate.
Sex and love have attracted prurient and clinical interest for millennia. Freud, Krafft-Ebing, Clelia Duel Mosher, Kinsey, Masters and Johnson, and Frank Beach concentrated on sex. Love moved into the spotlight with Sen. William Proxmire’s 1975 Golden Fleece award to Berscheid and Walster.
As a social interaction, love exhibits multiple forms that sometimes have little to do with mate choice, as in arranged marriages. What are these in an individual? Should they be viewed as drives or emotions or a combination? And where does love originate at the biological level, if at all—with genes, hormones, or brain structure?
Looking at love at its biological, psychological and social levels can help to clarify what we’re talking about when someone mentions love. If we are still challenged by Elizabeth Barrett Browning’s “How do I love thee? Let me count the ways,” we will have to add genetic, hormonal, assortative, personality-linked, and social or cultural expressions to her list.
BIO: Love may be in our DNA. Sexual reproduction entails sexual arousal, a physiological response to a potential sexual partner. The response is not altogether a matter of conscious choice, but of chemistry. Although human leukocyte antigen (HLA) differences were once thought to operate in both sexes, it was subsequently measured more strongly in women ; however, the sex difference may not be strong in relation to the social context of mating (research here). If your potential partner’s nose is plugged, try a kiss. (It’s a saliva thing.)
The desirability of a mate is strongly influenced by cultural standards. Even studies that emphasize near-universality in criteria for beauty admit variations, while others argue strongly against universality.
We sometimes attribute attractiveness to mathematical ratios. The effect of a waist-to-hip ratio of 0.7 for women and a shoulders-to-waist ratio of 1.618 for men can also be seen as evolutionary cues to good health and fertility. There’s more to attractiveness, of course, some of it rather mysterious. Hormones that helped to shape the body remain important in adulthood in different ways. Some facial features are hard to reduce to a formula. Ratios can apply not just to skeletal proportions but to subtler features like contrast.
Where the focus (so to speak) has been on attractiveness as a biological trait, a common argument is that evolution may have favored shape over size. The apparent value of prominent buttocks may result from the small waist-hip ratio, as it’s euphemistically called, rather than size alone. The waist-hip ratio may be a criterion of female attractiveness around the world (scroll down for the article), though it’s perhaps not universal.
Unfortunately, the speculation has outrun the evidence. It’s a relief to see someone, a biologist, treat the overly zealous “researchers” with very limited respect.
PSYCHO: In the ancient world there were four kinds of love, or maybe eight, which can be easily confused with eight (or more) ways of expressing love. Aside from cultural conventions, the purpose of any form of love must ultimately have been to perpetuate the species—by mating more often, protecting infants, and caring for the sick.
How many forms of love would be required for mate selection? As the label implies, we are selective in choosing mates. This is called assortative mating. However, we are selective in many ways. We want our mates to be attractive, healthy, pleasant to be with, socially acceptable, and so on.
Love is not an all-purpose tool, and we can narrow its focus a bit. The search for a mate is a form of motivated behavior, and since Charles Sherrington wrote about it, we have distinguished two stages of motivated behavior, appetitive and consummatory. Appetitive behavior is the search for fulfillment, and consummatory behavior hits the spot. The appetitive approach to mating, or courtship, is driven by erotic arousal, or lust. It is relatively unselective, and it generalizes to people who resemble the object of one’s affections. Consummation of the appetitive search is mating and companionship. This romantic love is more selective. There’s some evidence that the difference between lust and love can be revealed in the gaze.
An argument that has run on for decades on the sidelines is whether love is a drive or an emotion. While Helen Fisher has argued that love is not an emotion, others have taken a contrary position. By now we should be suspicious of using one label, “love”, to apply to different kinds of behavior. Love as lust, an appetitive drive, seems to generalize easily (with alcohol or without) to anyone similar to an exciting person, while love as companionship and intimacy does not, even though emotions often generalize. However, romantic or companionate love appears to have a stronger cognitive component than most emotions.
SOCIAL: A fairly comprehensive description of love appeared in this German documentary (dubbed into English). It focuses mostly on love rather than lust.
I’m also pretty sure that I could pick out the best-looking headlights, dashboard fascia, and so on to put together the most attractive car and it would look at least presentable.
If attractiveness were a physical trait, could an observer pick out the most attractive nose from a selection of noses, the best hair from a panel of hairstyles, and continue to build what anyone would agree is the most attractive person?
On the contrary, beautiful faces are incredibly average, according to some research!
This strange-sounding hypothesis is something you can check out yourself. (Click on “Averager”. Or go straight here.) One insight this has inspired is the cheerleader effect. As you might guess, we should not stretch the averageness hypothesis too far.
Our notions of beauty and its secrets have a long history, even in academic research. We appreciate beautiful faces because they are easy to process, for one thing–maybe because of their symmetry. On the other hand, symmetry is a cue to health and personality as well.
Agreement about who’s hot and who’s not is contagious. I wonder if we could refine the question to ask if attractiveness were a biological trait it would have to be an assemblage of perfect parts, or if it were culturally determined it would have to be holistic, reflecting the sum of many behavioral factors and many parts of the brain? Caught between hormones and cultural guide rails, love as Shakespeare discerned it was like a bad Hollandaise sauce, and never did run smooth.