(Mackenzie - 2006)The Brain in LoveUsing neurochem

(Mackenzie - 2006)

The Brain in Love

Using neurochemistry to try to unravel the experience of romantic passion

By Barbara Smuts

Fisher is well known for her three previous books (The Sex Contract, Anatomy of Love and The First Sex), which bring an evolutionary perspective to myriad aspects of sex, love, and sex differences. This book is the best, in my view, because it goes beyond observable behaviors to consider their underlying brain mechanisms. Most people think of romantic love as a feeling. Fisher, however, views it as a drive so powerful that it can override other drives, such as hunger and thirst, render the most dignified person a fool, or bring rapture to an unassuming wallflower.

This original hypothesis is consistent with the neurochemistry of love. While emphasizing the complex and subtle interplay among multiple brain chemicals, Fisher argues convincingly that dopamine deserves center stage. This neurotransmitter drives animals to seek rewards, such as food and sex, and is also essential to the pleasure experienced when such drives are satisfied. Fisher thinks that dopamine’s action can explain both the highs of romantic passion (dopamine rising) and the lows of rejection (dopamine falling). Citing evidence from studies of humans and other animals, she also demonstrates marked parallels between the behaviors, feelings and chemicals that underlie romantic love and those associated with substance addiction. Like the alcoholic who feels compelled to drink, the impassioned lover cries that he will die without his beloved.

Dying of a broken heart is, of course, not adaptive, and neither is forsaking family and fortune to pursue a sweetheart to the ends of the earth. Why then, Fisher asks, has evolution burdened humans with such seemingly irrational passions? Drawing on evidence from living primates, paleontology and diverse cultures, she argues that the evolution of largebrained, helpless hominid infants created a new imperative for mother and father to cooperate in child-rearing. Romantic love, she contests, drove ancestral women and men to come together long enough to conceive, whereas attachment, another complex of feelings with a different chemical basis, kept them together long enough to support a child until weaning (about four years). Evidence indicates that as attachment grows, passion recedes. Thus, the same feelings that bring parents together often force them apart, as one or both fall in love with someone new. Fisher’s theory of how human pair-bonding evolved is just one of several hypotheses under debate today, and she does not discuss these alternatives. Like the words of a talented lover, Fisher’s prose is charming and engaging. One chapter is a litany to passion in other animals, a vivid reminder that we are not the only species that feels deeply. Another provides new insight into the obsessive attempts of abandoned lovers to rekindle romance. Toward the end of the book, Fisher helps to redeem the self-help genre, rooting her advice in hard science.

Image: BARBARA SMUTS

OLIVE BABOONS, an adult female (left) and male, snuggle during an afternoon rest period in Kenya. Among baboons, only pairs who have formed longterm friendships have been observed in such intimate contact.

(Adapted from http://www.sciam.com)

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