How Your Brain Falls In Love

### The Neurotransmitters of Love

At the onset of love, various neurotransmitters in our brains shift dramatically. Cortisol, the stress hormone, increases, making us feel nervous yet excited. Simultaneously, oxytocin—the so-called "love hormone"—rises, promoting feelings of affection and intimacy. Interestingly, a woman’s testosterone levels tend to rise, leading to increased assertiveness, while a man’s testosterone typically decreases, making him more passive. Additionally, serotonin levels drop for both genders, which can result in obsessive thoughts about the partner.

### The Mechanisms Behind Love

While we understand these biochemical changes, the exact mechanisms that lead to them remain somewhat elusive. During a family vacation, I spoke with my cousin, a biochemist, about love's biochemistry. We discussed whether certain tipping points or enzymatic reactions might play roles in the process of falling in love. Just as I was about to ask another question, my grandmother, at 95 years old, chimed in, claiming that "youngsters don’t know anything about love." This sparked a fascinating dialogue about how men and women might experience love differently.

### Generational Wisdom on Love

My grandmother shared her belief that women often rush into intimacy, which could impede the development of deeper emotional connections. She insisted that men need time to develop feelings, suggesting that delaying sexual intimacy could lead to a more profound bond. This concept reminded me of popular dating advice like the "three-date rule" or Steve Harvey's "90-day rule," which I had previously thought were just anecdotal.

Curious, I asked her how long one should wait before becoming intimate. She advised waiting until a man falls in love, which she equated with his commitment. While I found this perspective intriguing, my cousin seemed skeptical, raising questions about its scientific validity.

### The Research Challenges

Research on how humans fall in love is limited, mainly due to the complexities of studying emotional states. Most studies rely on animal models, particularly monogamous species like prairie voles, which mate for life and can provide valuable insights into the neurochemistry of love.

### Understanding Neurotransmitters in Animals

In studies of prairie voles, researchers discovered that dopamine levels increase when they find a mate. This increase in dopamine is critical; when blocked, the voles lose their affectionate feelings. However, dopamine alone cannot explain human romantic love, as it also spikes during other pleasurable activities, like gambling.

Researchers shifted their focus to oxytocin, which is known to enhance bonding, especially in mother-child relationships. When a female prairie vole finds a mate, her oxytocin levels surge. However, testosterone complicates this relationship for males, as it can inhibit oxytocin’s bonding effects.

To address this, scientists examined vasopressin, a hormone similar to oxytocin. They found that when prairie voles were given vasopressin, blocking it resulted in a loss of affectionate behavior, suggesting it plays a vital role in male bonding.

### Translating Findings to Humans

What does this mean for human relationships? Research suggests that dopamine and oxytocin are crucial for women, while men rely more on vasopressin and testosterone. For women, dopamine increases during dating, leading to feelings of excitement and anticipation. Oxytocin, known as the "cuddle hormone," builds through trust and physical affection and spikes during orgasm. This aligns with my grandmother’s advice about waiting before becoming intimate.

For men, dopamine also increases in enjoyable relationships, but vasopressin levels rise through sexual stimulation. However, unlike oxytocin, vasopressin levels decrease after sex, complicating how men develop lasting feelings.

### The Role of Commitment

A study by the United States Air Force examined testosterone levels in over 2,000 servicemen, revealing that single men had higher testosterone levels than their married counterparts. This suggests that testosterone drops upon commitment rather than just marriage. Further studies from Harvard supported this by showing similar testosterone levels among married men and those in committed relationships.

This suggests that commitment—rather than marriage itself—plays a critical role in male attachment, reinforcing my grandmother's insights. Women may fall in love more easily through physical intimacy, while men often develop deeper feelings through commitment.