Human affection manifests in three distinct but interrelated systems: lust, driven by the desire for sexual gratification; attraction, which narrows our focus to a single partner; and attachment, the bond that leads to long-term companionship. Each system is associated with different hormone activities, such as testosterone and estrogen for lust, dopamine and norepinephrine for attraction, and oxytocin and vasopressin for attachment. Understanding these systems can help explain the complexities of human relationships and the challenges they often face.

Attraction is influenced by a mix of factors, including the allure of the unknown, the appeal of those who are different from us, and the innate preference for symmetrical features. Mystery can fuel romantic interest, as it invites curiosity and exploration. Differences, whether cultural or personal, can be intriguing and sexually exciting. Symmetry is often subconsciously associated with genetic health and fertility, making it a key factor in physical attraction.

Evolutionary psychology suggests that gender differences in mate selection are rooted in ancestral survival strategies. Men's preference for physical attractiveness may be linked to cues for fertility and health, while women's preference for intelligence and resources could be tied to securing support for child-rearing. These tendencies, while not absolute, have been observed across cultures and may be influenced by societal norms and individual experiences.

'Love maps' are mental frameworks that outline the specific characteristics we seek in a partner. These maps are shaped by personal experiences, cultural expectations, and biological predispositions. They guide us, often subconsciously, in choosing a mate and can explain why certain individuals appeal to us more than others. These maps are unique to each person and can evolve over time as we encounter new experiences and insights.

The concept of romantic love may have served an important evolutionary function by promoting pair-bonding and cooperation between partners, aiding in the survival of offspring. This theory suggests that love evolved as a mechanism to keep parents bonded long enough to raise children together, providing a stable environment for the next generation.

As human societies evolved, so did the concept of love, adapting to different social and environmental pressures. Romantic love may have contributed to social cohesion and the establishment of familial units, which were crucial for the survival of early human communities. The evolution of love has had profound implications for social structures, influencing marriage practices, family dynamics, and even economic systems.