What causes romantic chemistry between people? One of the answers could lie in how we smell. According to anthropologist Helen Fisher, one of the ‘most important modern scientific studies’ in the field of human relationships involved a sweaty T-shirt.

Biologist Claus Wedekind asked female students to smell men’s clothes, which had been worn without deodorant, in order to discover whether our attraction to someone was influenced by their scent. He found that it was. We overwhelmingly prefer the smell of people who have a dissimilar immune system to our own. Wedekind’s study proved what many evolutionists had been claiming for years — our attraction to others is physical. The shape of someone’s jaw, their scent, or the pitch of their voice might attract us because chemistry is all about finding a good genetic match.

But there is another important kind of alchemy at work — the pull of a deep emotional connection. The feelings of affinity that we share with certain people in our lives are often more intense than our reaction to their looks. This is what causes romantic chemistry between people and influences not only which people we are drawn to, but also which people will push us away. Crucially, it is also something we can enhance. It isn’t about pretending to be something we’re not, but about changing the way we let people know who we really are.

Do opposites attract?

Many relationship experts suggest we’re more likely to click with someone because of our similarities. Feeling affinity is often crucial to the success of a relationship. ‘You’re going to understand that person better if you share the same views,’ says psychologist Dr Gian Gonzaga of eHarmony Labs. ‘In the long term, being opposite to someone makes it more difficult to negotiate a relationship, because you always have those differences that you need to negotiate again and again.’

But those couples who seem to be polar opposites may be driven by a different kind of motivation — one that psychologists call the Michelangelo phenomenon. Just as we have an ideal version of a partner, we also have an ideal vision of ourselves, and we often seek out someone who will ‘sculpt’ us in a way that will help us reach that ideal vision. We meet someone who appears to be very different from us on the surface, but we’re drawn to them because something in us recognises a trait in them that we feel we lack, hence the quiet man with the extrovert girlfriend.

Reveal your true self

In certain situations our first instinct is often to try to positively influence other people’s perceptions of us. For example, we might tell white lies about our hobbies to make us seem more interesting at dinner parties. This kind of manipulation is generally harmless. If you’re what is known as a high self-monitor (HSM) — someone who is good at judging other people’s opinions and adapting to fit in — then it’s likely you’re the kind of person who thrives in team situations and enjoys the company of many different friends. This is the sort of person you might expect to be good at creating chemistry.

But when it comes to forging deeper connections, HSMs can find it difficult to enjoy the same levels of intimacy. Their talent for adapting and concealing different parts of themselves means they are reluctant to disclose any genuine information. A 2007 review found that HSMs were less likely to have intimate conversations with their partners and had lower levels of trust. If we want to experience true chemistry, we have to reveal our true selves.

Negative traits can also attract us

‘By our teenage years, each of us has constructed an idiosyncratic catalogue of traits, values, aptitudes and mannerisms that appeal to us,’ says anthropologist Helen Fisher. But, she argues, this doesn’t always mean that those traits are positive. ‘Take the girl who has an alcoholic father and as a child she grows up getting used to the unpredictability, the spontaneity, the chaos, and she says, “I’m never going to marry a guy like that”. So she doesn’t marry an alcoholic, but what she does is marry a busy artist who’s up all night. If you’d asked her what she was looking for in a partner, she wouldn’t say ‘unpredictable’ — but she’s used to unpredictability. It’s part of her love map.’

The intricacies of our love maps mean that we may not be aware of our negative impulses, but it is possible that as we grow older and more experienced, we’ll develop better judgement.

Romantic chemistry doesn’t have to be instant

What causes romantic chemistry between people doesn’t always happen instantly. We don’t always click with someone the first time we meet them, but that doesn’t mean we won’t at some point in the future. Some of the most fulfilling connections are the ones that happen later. ‘Kate joined our company a month after me, and I always had the feeling that we could be good friends, but she worked in a different department,’ says Jude. ‘Then one day, we happened to have a meeting together and I noticed a book by my favourite author poking out of her bag. I asked her what she thought of it, and her eyes lit up. From there, the conversation flowed.’

Discovering new connections like this can feel thrilling because someone else is validating us. ‘This can be critical in a relationship, because we humans have a need to believe that our world view is correct,’ says Gonzaga. ‘So when someone confirms that, we like that person more.’

Can we also have anti-chemistry?

We might meet people whom we should like, but there’s something about them that drives us away. On paper, we have things in common, we share the same goals, but we cannot see past what appears as a glaring flaw in their personality. ‘This is often about what you project on to other people,’ says psychotherapist Toby Ingham. We tend to interpret other people’s behaviour through the filter of our own experience and see in them only what we want to see — what fits with our “script”.’

In the case of negative attraction, the people we meet whom we reject, it may be that we perceive something in them that echoes a trait we don’t like in ourselves, suggests Ingham, and we’re often more finely attuned to our own flaws. ‘What we like and what we don’t like in other people is also partly motivated by our envy of them,’ he says. When our first reaction is to feel hostility, it could be because that person represents something we want, or because we sense that they could threaten our social standing.

Photograph: BananaStock

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