Love is often characterized as a mix of different emotions that include passion, devotion, attachment, admiration and desire. It is a highly complex emotion that can be hard to define. Some psychologists describe it as a secondary emotion that derives from a mixture of primary feelings and emotions, while others believe that it is a distinct emotion all its own.

Love has been a subject of philosophical speculation, poetry and high school boys gazing dreamily at the girl two rows over since humans first walked the earth. Today, scientists are beginning to understand its true nature, though they still have a long way to go. From a scientific perspective, there is much to learn from the brain scans of those in lust or infatuation. They show that love activates a jumble of chemicals that make your stomach flutter, your palms sweat and your heart race. These chemical reactions are triggered by the release of a slew of hormones including dopamine (pleasure), adrenaline (fight or flight) and norepinephrine. When these are replaced by oxytocin, known as the “cuddle hormone” in humans, you start to feel bonded to your love interest.

In this stage, you tend to focus on the good traits of your loved one and minimize their bad attributes. You might also become more obsessive about the person and seek out opportunities to spend time together. You might even begin to want to change them in ways that you think would improve their quality of life. This is a stage of commitment and intimacy that can lead to sexual desire and feelings of intense possessiveness.

The ecstasy and giddy high of this phase may fade as the demands of daily life refocus your attention. However, if you communicate well with your partner about problems and expectations in the relationship, compromise when necessary and share some commonality on core beliefs, the emotional connection can remain strong. This is a strong form of love that many people envision when they think about marriage and spousal relationships.

The biology of love might be more complex than the simple feedback mechanisms posited by some scientists. Perhaps the oxytocin involved in mate-guarding, bonding and social interaction is just one part of a neurochemical system that enables the human brain to respond to visceral experiences and create its own reality. The human brain evolved from primitive parts of the nervous system that are able to respond more rapidly and intuitively to raw visceral input than the modern cerebral cortex can process, and love might be an attempt by our bodies to compensate for this evolutionary shortcoming. The fact that we can still find the strength to stay committed to a person, even when they fall into destructive patterns of behavior, is testimony to the power and endurance of true love.