Contents: criticism, research (googling), insights.

A lot of times on TRP we act as if love for the sake of love is impossible and that all our decisions are, at the primal subconscious level, economic. We like to cite testosterone and male biology as the cause of male sexual behavioral patterns, for example polygamy. Similarly, we like to cite a woman's monthly hormonal cycle and burdensome pregnancy and other aspects of female biology as the cause of female sexual behavioral patterns. For the most part, this economic unemotional perspective of human behavior has been nothing short of enlightening. However, there is another aspect that I feel that the more biochemically-adept members of TRP have neglected; this is the realm of oxytocin!

Oxytocin is a hormone produced by the hypothalamus. Because it is a hormone, it travels through blood and therefore to the whole body. As a result, it has many effects on the body and one's behavior.

I quote the following from Stephanie Pappas from Live Science:

"Oxytocin in women

Oxytocin is a particularly important hormone for women. "Oxytocin is a peptide produced in the brain that was first recognized for its role in the birth process, and also in nursing," said Larry Young, a behavioral neuroscientist at Emory University in Atlanta, Georgia.

The hormone causes uterine contractions during labor and helps shrink the uterus after delivery. When an infant suckles at his or her mother's breast, the stimulation causes a release of oxytocin, which, in turn, orders the body to "let down" milk for the baby to drink.

Oxytocin also promotes mother-child bonding. Studies show that "female rats find pups to be aversive if [the females are] virgins," Young told Live Science. "But once they give birth, the brain is transformed, so they find the pups irresistible," he said. And similar findings are seen in humans.

A 2007 study published in the journal Psychological Science found that the higher a mom's oxytocin levels in the first trimester of pregnancy, the more likely she was to engage in bonding behaviors such as singing to or bathing her baby.

Although maternal bonding may not always be hardwired - after all, human females can adopt babies and take care of them - oxytocin released during pregnancy "does seem to have a role in motivation and feelings of connectedness to a baby," Young said. Studies also show that interacting with a baby causes the infant's own oxytocin levels to increase, he added.

Oxytocin in men

In men, as in women, oxytocin facilitates bonding. Dads who got a boost of oxytocin via a nasal spray played more closely with their 5-month-old babies than dads who didn't get the hormone zap, a 2012 study found. (There is another hormone, called vasopressin, which plays a stronger role in men.)

Another study found that men in relationships given a burst of oxytocin spray stood farther away from an attractive woman than men who weren't given any oxytocin. Single men didn't see any effect from the hormone, suggesting oxytocin may work as a fidelity booster for guys who are already bonded with another woman.

This anti-social effect of a social hormone brings some nuance to the story of oxytocin. In one study, researchers found that Dutch students given a snort of the hormone became more positive about fictional Dutch characters, but were more negative about characters with Arab or German names. The finding suggests that oxytocin's social bonding effects are targeted at whomever a person perceives as part of their in-group, the researchers reported in January 2011 in the journal PNAS.

In another study, published in PNAS in 2010, men were given a dose of oxytocin and asked to write about their mothers. Those with secure relationships described their moms as more caring after the hormone dose. Those with troubled relationships actually saw their mothers as less caring. The hormone may help with the formation of social memories, according to the study researchers, so a whiff strengthens previous associations, whether good or bad.

"My view of what oxytocin is doing in the brain is making social information more salient," Young said. "It connects brain areas involved in processing social information - whether it's sights, faces, sounds or smells - and helps link those areas to the brain's reward system."

End quote.

After further research, I made a rough list of oxytocin's effects.

Improves Social bonding/attachment

Eases stress

Increases sexual arousal

Reduces drug cravings

Improves social skills

Triggers protective instincts

Induces sleep/tranquility

Fosters generosity

Improves social recognition

Improves trust

In women, it is implicated in milk secretion

Causes longing for your loved ones

It is important for mothers because it plays a role in child birth and social bonding between the baby and its mother (nipple stimulation triggers its release). For couples, prolonged eye contact and sex (use this) has been found to increase its release. Scientists in 2013 further discovered another role in monogamous voles. Essentially, oxytocin was found to increase monogamousness in voles in a positive feedback loop. When away from their partners, people experience oxytocin withdrawal.

Furthermore, scientists recorded hormone fluctuations throughout the day in a tribe of men from Bolivia who hunted. Testosterone was high after they killed the animal until they returned home. Oxytocin was high when the men were with their families.

Basically, the presence of this hormone literally will make you love anyone who you spend time with. So ONEitis is still an illusion because anyone who you spend time with can cause its secretion. Breakups are painful even with the abundance mentality. Men love women and women love children can be seen here because the oxytocin-breastfeeding mechanism makes women 'love' their young children more than men. Also, this is why arranged marriages can work; people will tend to 'love' each other over long periods of time (so long as hormones are working). Lastly, stop texting her and stare into her soul.

I just wrote this in an hour so expect edits.

TLDR; 'love' exists because of oxytocin