All we need is love the women say. Love is blind people say. Love moves the world around is a famous saying. Our lives either we accept it or not have the pursuit of love as one of their greatest priorities. Sometimes we consciously try to avoid it even though there is a strong drive that makes us look back. But what does it mean to be in love? In romantic love. Is it a divine feeling that god has given it as a present to humans? Is it a way to find a true meaning in life? Is it the antidote to melancholy and to low self-esteem? And above all, can we determine what it is or we can just sense it and know that it’s there? These butterflies in the stomach? Personally, I remember that for several times in the past, when asked if I was in love, I would reply that I didn’t know.
Charles Darwin in his prominent book “The Origin Of Species” describes that people had many times noticed situations like male alligators fighting, bellowing, and whirling round, like Indians in a war-dance, for the possession of the females; or the males of certain hymenopterous insects have been frequently seen fighting for a particular female who sits by, an apparently unconcerned beholder of the struggle, and then retires with the conqueror. Even at the 1850s many animal observers believed that there is the severest rivalry between the males of many bird species to attract, by singing, the females like the birds of paradise from the rock-thrush of Guiana. Darwin named this process sexual selection and described that this form of selection depends on a struggle between the individuals of one sex, mostly the males, for the possession of the other sex. More than a century later Dr. Robert Trivers explained why in most species the females were choosier.
After this you can understand that it was very important for organisms to have evolved efficient mechanisms to achieve the optimal reproductive success. This means to give birth to healthy and fertile offspring by picking, of course, the most suitable mate. Since the mammalian courtship had been observed to have several similarities with human romantic love the scientists first proposed that there would be the same hormones and similar brain activities involved in the process. The recent years with the use of modern technologies like FMRI they have been studying the human brains to find out if they have a specific design and what kind of functions, that motivate the organism to focus on his genetically predetermined “duties”, in our case the reproduction.
Dr. Helen Fisher from the Rutgers University has conducted several experiments with the use of FMRI examining the brains of people who were admitting they were passionately ‘in love’(2000, 2006, 2007, 2011) . But first and foremost she had proposed the existence of three different emotional mechanisms, three distinct brain regions in humans, in the other mammals and in the avian species that motivate the individual to mate, reproduce and parent. Dr. Donald Pfaff (1999) defines a drive as a neural state that energizes and directs behaviour to acquire a particular biological need to survive or reproduce. Even though, each system refers to a different constellation in the brain and each one evolved to direct a different aspect of human mating, they sometimes interact between them. Fisher’s identification made the whole picture much clearer and you are going to understand why below.
It may also be referred as the sex drive. This is the craving for sexual gratification with a range of partners. It is triggered by myriads of ethical, physiological, psychological etc stimuli but is mostly associated with the androgens. Human males with higher circulating levels of testosterone have a higher sex drive whereas the females have more sexual desire around the “ovulation window” of every month when the testosterone levels are at their highest. The balance between the androgens, the oestrogens and other biological and environmental factors play a role when and how often an individual expresses the sex drive. It has to be stated that the gratification of the lust doesn’t necessarily result in mating. Mating has to do with another mechanism (The Attraction System) and the mechanisms act largely distinctively with each other. If you inject people with testosterone you will for sure enhance their sex drive but you cannot be sure if they will fall in love. This has to do with several other biological and environmental factors, too.
The Attraction System (Romantic Love)
This system called, as well, passionate love, or romantic love, or infatuation motivates the individual to focus his/her attention to a specific one mate or potential mate that has picked as a preferable partner. It is an energy conservation system through which the individual saves courtship time and metabolic energy by choosing among the potential mates the genetically superior ones. It is, also, characterized by feelings of exhilaration, intrusive thinking about the love object and craving for emotional union with the partner. When people are in love tend to believe that their mate is the special, is unique and they report thinking about their love even up to 85% of their waking hours (Tennov, 1979). This is an evolutionary safeguard that helps concentrate the energy to the one, as previously mentioned. Moreover, the beloved ones exaggerate the positive characteristics of their mates and overlook their negative traits. The above come as a result of the neurotransmitter called dopamine that activates the reward circuit of the brain and is generally associated with goal directed behaviors and anticipation of pleasure. The dopaminergic effect in the brain, as well, makes the situations more memorable. That’s why the people in love in Helen Fisher’s experiments remembered trivial things that their mate said and did. Increased concentrations of dopamine have been associated, as well, with euphoria, loss of appetite, hyperactivity and delay of onset of fatigue and anxiety and panic. Do these ring any bell?
The above increased memory capacity and many other outcomes come as a result of the hormone norepinephrine (noradrenaline), too, which was reported to be increased in the ones in love. Also, the people in romantic love were measured to have decreased levels of the hormone serotonin which was confirmed to be associated with obsessive love and intrusive thinking about the partner (Marazziti et. al, 1999). Serotonin reuptake inhibitors are the main agents of choice when trying to treat people with obsessive compulsive disorders and intrusive thinking is definitely a form of obsessive behavior.
The bad news are that when scientists retested the brains of the ones in love they found that 12-18 months after the beginning of the romance the serotonin levels had reached the same levels of the control group meaning that romantic love is lost or almost gone after this period in human beings.
In the animal kingdom we can notice attached mates to share parental duties, maintain close proximity and defend their territory. In humans they are, also, characterized by calmness, emotional union, close contact and display of separation anxiety when apart. Several neuropeptides are involved in the feelings of attachment but the recent literature defines the most important hormones to be vasopressin and oxytocin. A variety of studies suggest enhanced vasopressin function in males versus females, including research in humans, rats, hamsters and prairie voles whereas oxytocin tends to be higher in females. Vasopressin is associated with this energetic pursuit of the mate. Oxytocin has to do with feelings of empathy and are helpful for the mother to “connect” with her child.
Through the about 4 millions years of our evolutionary past, human females needed help in the nurturing of their babies. They were bipedal and had to carry the babies on their hands instead of backs when they were wondering in the plains of Africa. At the same time the dangers of this environment were deadly and the food scarce. So much that the existence of a pair bond was crucial at least for the time that the child was too young. Natural Selection, then, had to have favored the existence of a mechanism that drives people to remain together for that amount of time. Attachment, thus, is proved to be a motivation for mating partners to sustain an afﬁliative connection long enough to complete their parental duties
Even though long-term attachments are observed, divorces are common among societies worldwide. The interesting thing is that worldwide data gathered among 62 societies showed that most marriages tend to dissolve after the 4th year and the people in a reproductive age tend to remarry. These four years are the breast-feeding and infantry years of the child. They, also, confront to the traditional period between human successive births. So it has been proposed that in our evolutionary past the couple should have remained at least for these years together. Afterwards, the child could enter a multi age group in the tribe and the other siblings could help in parenting. If the couple didn’t have other children they were free to separate and increase their genetic variability by picking another partner. This seems to be the way we have been shaped over millions of years and this is how humans managed to exist till today. The whole observation shows that people tend to be serial monogamists. This tendency for humans to divorce maybe comes from an overstimulation of the oxytocin and vasopressin receptors leaving one susceptible to separation. After the first 4-year cycle closes another can open with the sex drive, afterwards a romantic love phase that would lead to attachment and thus to marriage.
Divisions between romantic love, lust and attachment.
As previously mentioned the attraction system shouldn’t be confused with the sex drive one because they work separately. A person that engages in short-term sexual intercourse doesn’t mean that is in a romantic love with this person. Romantic love is a mechanism designed for a choice of a specific individual whereas the sex drive motivates us to generally focus on reproduction. The sex drive motivates us towards a sexual union but the attraction mechanism leads us to an emotional one. Don’t forget that love overcomes the sexual desire. The latter can be “silenced” for some times whereas love should remain unaffected at the first 12-18 months at most. And of course this division between the two brain parts is proved to be the reason many people are in a romantic relationship but at the same time are able to have short-term sexual intercourses without committing to them.
Same happens with the sex drive and attachment. All mammalian species engage in copulation but only 3% form long term bonds (Kleiman, 1977). Humans can definitely express their sex drive to individuals they are not attached and can show nice feelings and be attached to a mate or spouse that have no sexual desire at all.
This distinction of the drives has helped humans to be more effective in their reproductive chances. This has to do with a brain designed to tend the organism towards extra pair mating outside the long-term relationship. In strict evolutionary terms the adulterous man can give birth to more offspring. An adulterous woman can create and maintain very close friendships that can help with the extra provision of food and security. At the same time extra marital affairs could provide women with differentiated and/or greater genes.
Connections between emotional systems that motivate effective reproduction
The three brain systems are distinct yet have biological interrelations. For example, animal studies have shown that increased levels of dopamine in the brains of rats stimulate a cascade that results in the secretion of testosterone and estrogens (Wenkstern et al. 1993; Hull et al. 1995, 1997). The opposite happens, too (Hull et al. 1999; Appararundaram et al. 2002). Similar findings exist for people. When individuals exhibiting hypoactive sexual desire disorder are treated with dopamine-enhancing medications, sex drive increases (Segraves et al. 2001). When patients suffering from depression take drugs that elevate central dopamine activity, their libido often enhances (Walker et al. 1993; Ascher et al. 1995; Coleman et al. 1999). All the above mean that activity in the sexual drive system can result in activity in the romantic love system and the opposite. In simple words, a short-term sexual intercourse can under appropriate circumstances evolve to romantic love. Also, romantic love can stimulate the sex drive.
There are, also, interactions between the attachment and the romantic love “centers” of the brain. For example, central dopamine (and norepinephrine) can stimulate the release of oxytocin and vasopressin (Kendrick et al. 1992; Ginsberg et al. 1994) but increasing activity of central oxytocin can stimulate release of norepinephrine and dopamine (Kendrick 2000). All the above show that an individual can engage in a short-term relationship primarily sexually oriented. Afterwards this activity can lead to a romantic love through the positive correlation of the two systems. If everything goes well it can result in a long-term attachment through the positive correlation of the neural regions that are involved in love and the ones that are involved in attachment. The above can be explained biologically by the fact that after orgasm men’s levels of vasopressin and women’s levels of oxytocin increase (Damasio, 1994)
Sex drive, however, can have a negative impact on feelings of attachment. When scientists injected male sparrows with testosterone they all left their mates and pursued others (Wingfield, 1994). Men with higher testosterone levels marry less frequently and divorce more often (Booth and Dabbs, 1993). Man’s levels of testosterone, as well, increase when his marriage becomes unstable (Booth and Dabbs,1993) and they plunge when his expecting baby is born (Blum, 1997).
The above are one of the explanations why couples in long-term marriages express less sexual desire. It seems that their increased levels of vasopressin and/or oxytocin suppress their testosterone. Or mothers report a lack of sexual desire after parturition. That’s maybe because the levels of oxytocin are increased due to the birth of her child resulting in a decrease in her testosterone levels.
Romantic love is not primarily an emotion, but a motivation system designed to enable suitors to build and maintain an intimate relationship with a preferred mating partner. ~Arthur Aron