Love is a special sort of chemistry. Everyone relates love to feelings, emotions and attachment, but it also involves a play of hormones. However unromantic it may sound, it is true. Hormones are what makes the world go around.
It is said that love is blind and is often not under our control. A clue to this is hidden deep in human evolution. For survival, the human's brain has a reward system designed to make people do what they ought to. By making acts of survival and procreation pleasurable, nature has ensured that the human race survives forever.
Many hormones and brain chemicals are involved in different phases of love—lust, attraction, attachment, craving for sex, mating and parenting. There is a common misconception that only sexual glands are involved in regulating these processes. However, other endocrine glands (example, pituitary and adrenal gland) have important roles, too. Broadly the process of falling in love can be divided into three stages.
Stage 1 Lust
Male and female hormones (testosterone and oestrogen) are key determinants of desire for intimacy. These hormones are produced in testis in men and ovaries in women and they are responsible for sex drive and maintaining our reproduction during the active period of life. Interestingly, the male hormone testosterone has a major role to play in women's libido, too.
Stage 2 Attraction
The next time when you go weak in the knees or your heart beats faster when you see someone attractive you can attribute it to the adrenal glands. Adrenal hormones—cortisol and adrenaline—enable our body to survive in stressful situations. Thus a person who is love-struck can stay without sleep and food for long periods. Though the physical reaction to attraction is controlled by adrenal glands, your emotions and feelings are regulated by substances like dopamine and serotonin. These active compounds are produced in brain and stimulate excitement and desire. Not only do these hormones induce pleasure, they leave you wanting more and more. Drugs with addictive properties have been designed based on the structure of these hormones. These chemicals compel the person in love to persistently think about the partner and make him or her oblivious to the surroundings or environment. This is exactly the feeling of being “lost in love”. Your partner becomes the sole object of desire and adoration for you.
Stage 3 Attachment
It allows couples to bond and be together long enough to have children and raise them. This is mediated by oxytocin and vasopressin, hormones released by human brain. Oxytocin is a hormone released during orgasm, and by women during childbirth. It not only induces bonding between couples but also creates a strong bond between a mother and her child. Attempts have been made to develop oxytocin sprays to enhance attraction between sexes. Vasopressin is released after sex and some suggest that it may have a role in maintaining long term relationships.
All this chemistry of hormones is not as simple as it may seem. There are complex interactions between hormones. Elevated testosterone can suppress oxytocin and vasopressin. Research suggests that men with higher testosterone levels tend to marry less often, be more abusive in their marriage, and seek divorce more often. And vice-versa can also be true.
While all this appears very exciting and interesting, it is still not totally clear as to whether these hormonal changes trigger our responses or it is our mental or emotional state that induces these hormonal changes.
The author is chairman, division of endocrinology and diabetes, Medanta Medicity, Gurgaon.