In humans, brain regions associated with dopamine are activated in mothers looking at pictures of their children, and lovers at each other — and, perhaps instructively, in drug addicts taking heroin or cocaine.

To Young, all this means that science may soon treat lovelessness as easily as it now treats depression and anxiety. "Drugs that manipulate brain systems at whim to enhance or diminish our love for another may not be far away," he writes.

Not so fast, said Fisher.

The alterations required to manipulate love, she said, are likely so complex and far-reaching as to be unattainable in a pill. "There are cognitive processes and limbic reactions associated with basic emotions," said Fisher. "And you can change brain chemistry, but you're still not going to change memories and experiences in a human being."

It,s good to know some things can still be left to nature.Romantic efforts of a determined heart will win some loose some just as its always been.