My insatiable desire for sex cost Maggie her degree

Millions of words have been written over thousands of years about the mysteries of love. Not any more, if Stephanie Cacioppo has her way. A neuroscientist who argues that human brains are wired for love, Cacioppo spends her days in a lab working out exactly what love does to the brain, and how and why we need it. But when she told her academic supervisors of her wish to specialise in love, they laughed.

“They were disappointed and surprised,” she says on the phone from Chicago. “They thought love was a simple mechanism that you couldn’t study, a soft science, but there is nothing more complex than love. It is a biological necessity. Just as we need clean water or nutritious food, we need to love as well.”

Cacioppo, 47, began her research into love — or “career suicide”, as one colleague called it — in 2006, at Dartmouth College in New Hampshire. She posted flyers around campus reading: “Wanted! Women in love.” When they turned up, she scanned their brains for an hour while they watched various images: a picture of their partner, or just his or her name, or pictures of good friends or total strangers. Every time it was an image of their partner “the brain activity was like fireworks” and was measurably more intense than when they looked at someone who was simply a very good friend.

Today Cacioppo is director of the University of Chicago’s brain dynamics laboratory, and the university’s assistant professor of psychiatry and behavioural neuroscience. Using scanners and high-density electrodes on the scalp, she attempts to map which of the brain’s 86 billion neurons are involved in love, and documents the profound physical and mental health benefits that it brings.

“We cannot realise our full potential as human beings without love,” she argues, listing the benefits. People who are in love sleep better at night and have better blood pressure. They tend to have a stronger immune system and recover better and faster from illnesses ranging from flu to cancer. Being in love makes you think faster and be more creative, it improves memory and it helps you to anticipate others’ actions better and faster, so the evolutionary benefits are obvious.

“If you can read people’s actions better, it’s extremely helpful from an evolutionary viewpoint because it helps the brain to save energy,” she says. “The brain aims to live for as long as possible, so it will try to save energy any time it can. That’s why being with someone you really love could help you perform better and think faster. Most of the benefits are subconscious.” Conversely, being lonely activates the same areas of the brain that register physical deprivation, like hunger or thirst.

Now Cacioppo has written a book, Wired for Love, incorporating her findings and drawing together studies by other academics, including research at Yale. Scientists there looked into the link between expectations and happiness, which Cacioppo argues also applies to the search for love. Volunteers played a decision-making game for small amounts of money. If they expected to win big, and they didn’t, they were unhappy. But if they had no expectation of winning, but nevertheless won a small amount of money, they were happy. Happiness, it seems, isn’t about the size of the prize, it’s about what you expect from the outset. So Cacioppo argues that when it comes to love, it isn’t about lowering your expectations, it’s about letting go of your preconditions.

“It’s about relinquishing the social pressures that lead you to pursue unrealistic expectations,” she says. In other words, it’s no use insisting that your future husband is tall, dark and works in the City, which everyone knows is unhelpful, but Cacioppo’s point is that it’s not entirely our conscious fault: it’s the way our brains work. Similarly, once you’ve found long-term love, she believes that it helps to remember that the brain is hardwired to crave novelty.

“So how do we make love last? By finding novelty every day and being curious about your significant other. Try to wake up every morning and look at your beloved with a fresh eye, to discover who they are today. The person you are with right now is not the exact same person you met ten years ago. They have evolved.”

Couples should beware not of the seven-year itch, she says, but the two-year slump. That’s when many couples move from the infatuation phase to one of unconditional love. That this period may well coincide with having children ramps up the pressure on the relationship, but Cacioppo has the answer.

“If people feel they are growing apart, knowing a little bit more about their brains could help. What they are experiencing is not necessarily their fault; there are biological reasons for it. If they leave guilt aside, and relax about the relationship, they may perhaps discover that the love that bonded them is still there.”

The irony of Cacioppo’s professional life is that personally she had no idea what love was. She had been contentedly single her whole life and thought she always would be. She viewed her lack of a love interest as “an interesting objective want in my search for love in the brain. I was really content to be single, and I wore my solitude as a badge of honour.”

Then, in January 2011, when she was working in Geneva, she met another neuroscientist, Dr John Cacioppo, at an academic conference in Shanghai. Like her, he studied relationships, and had co-founded the study of social neuroscience in the 1990s. But he was famous for his work at Chicago University into the dangers of loneliness. They embarked on a long-distance relationship and fell madly in love. He had been married and divorced twice, but for Dr Love, as she was becoming known, falling in love was like a fascinating experiment on herself.