Every man carries within him a world, which is composed of all that he has seen and loved, and to which he constantly returns, even when he is travelling through, and seems to be living in, some different world.
FRANÇOIS-RENÉ DE CHATEAUBRIAND, Travels in Italy, 1828
‘He won’t eat anything but cornflakes,’ complained the mother of a boy I used to know. Breakfast, lunch or dinner – always a bowl of cornflakes and milk. Even at other people’s houses, this boy made no concessions. To his mother, his extreme diet was a source of worry and exasperation. To the rest of us, he was a fascinating case study. Secretly, I was slightly in awe of him; my sister and I would never have dared be so fussy. To look at, you wouldn’t know there was anything different about this kid: scruffy blond hair, big grin, neither unduly skinny nor chubby. He was not socially withdrawn or difficult in any other way. Where did it come from, this bizarre cornflake fixation? It just seemed to be part of his personality, something no one could do anything about.
Whether you are a child or a parent, the question of ‘likes and dislikes’ is one of the great mysteries. Human tastes are astonishingly diverse, and can be mulishly stubborn. Even within the same family, likes vary dramatically from person to person. Some prefer the components of a meal to be served separate and unsullied, with nothing touching; others can only fully enjoy them when the flavours mingle in a pot. There is no such thing as a food that will please everyone. My oldest child – a contrarian – doesn’t like chocolate; my youngest – a conformist – adores it. It’s hard to say how much of this has to do with chocolate actually tasting different to each of them and how much it has to do with the social pay-off you get from being the person who either likes or loathes something so central to the surrounding culture. The one who loves chocolate gets the reward of enjoying something that almost everyone agrees is a treat. And he gets a lot of treats. The one who doesn’t like chocolate gets fewer sweets, but what he does get is the thrill of surprising people with his oddball tastes. He fills the chocolate-shaped void with liquorice.
Yet my chocolate-hating boy will happily consume pieces of chocolate if they are buried in a cookie or melted in a mug of hot cocoa. One of the many puzzles about likes and dislikes is how they change depending on the context. As the psychologist Paul Rozin says: ‘to say one likes lobster does not mean that one likes it for breakfast or smothered in whipped cream.’1 Different meals, different times of day and different locations can all make the same food or drink seem either desirable or not. Call it the retsina effect: that resinated white wine that is so refreshing when sipped on a Greek island tastes of paint-stripper back home in the rain. It’s also worth remembering that when we say we like this or that, though we use the same words, we are often not talking about the same thing. You may think you hate ‘mango’ because you have only ever tasted the fibrous, sour-yellow kind. When I say I adore it, I am thinking of a ripe Alphonso mango from India, brimming with orange juice and so fragrant you could bottle it and use it for perfume.
The foods we eat the most are not always the ones we like the most. In 1996 the psychologist Kent Berridge changed the way that many neuroscientists thought about eating when he introduced a distinction between ‘wanting’ (the motivation to eat something) and ‘liking’ (the pleasure that the food actually gives).2 Berridge found that ‘wanting’ or craving was neurally as well as psychologically distinct from ‘liking’. Whereas the zone of the brain that controls our motivation to eat stretches across the entire nucleus accumbens, the sections of the brain that give us pleasure when we eat occupy smaller ‘hotspots’ within this same area. For Berridge, this discovery offers a fruitful way for thinking about some of the ‘disorders of desire’ that bedevil humans. For example, binge eating may – like other addictive behaviours – be associated with ‘excessive wanting without commensurate “liking”’.3 You may feel a potent drive to purchase an extra-large portion of cheesy Nachos even though the pleasure they deliver when you actually consume them is much less potent than you expected. Indeed, binge eaters often report that the foods they crave do not even taste good when they are eating them: the desire is greater than the enjoyment.
However, several neuroscientists have pointed out in response to Berridge that liking and wanting remain ‘highly entangled’.4 Berridge himself admits that there is strong evidence that if you reduce the amount a food is liked, the consequence is that it is also wanted less.5 Even if our craved foods do not make us as happy as we hope they will, the reason that we crave them in the first place is because we once loved them.6 Like drug addicts, we are chasing a remembered high. Our ‘likes’ thus remain a central motivating force in shaping how and what we eat. To find out more about why we like the foods we do remains a vital question for anyone who is interested in feeding themselves or their family better. If asked to say where tastes come from, I suspect that most of us would say they were determined by individual temperament, which is another way of saying ‘genes’. Being a chocolate lover – or hater – becomes so much part of our self-image that we can’t imagine ourselves any other way. We show that we are adventurous by seeking out the hottest chillis; we prove we are easy-going by telling our host we ‘eat anything’. We confirm that we are naturally conservative by eating patriotic hunks of red meat. Taste is identity. Aged eight, my daughter used to draw pictures of herself and write ‘prawns-peas-mushrooms’ at the top, surrounding herself with the tastes she loved best.
Because our tastes are such an intimate part of ourselves, it is easy to make the leap to thinking that they must be mostly genetic: something you just have to accept as your lot in life. Parents often tell children that their particular passions place them on this or that side of the family – you got your fussiness from your grandfather! – as if you were destined from birth to eat a certain way. Sometimes it is uncanny how a suspicion of celery or a deep hunger for blackberries replicates from parent to child. When we notice these familial patterns, it confirms us in our view that food preferences must be inherited through our genes.
When I’ve described the argument of this book to people I meet, sometimes they get a little angry. ‘I disagree that we learn how to eat,’ they say. ‘You’d never get me to like sultanas/squid/salami [delete as appropriate].’ Anyway, they say, ‘What about genes?’
It’s fine by me if you don’t like sultanas. And I’m certainly not denying that there is a genetic component in our relationship with food. We are not born as blank slates. Some people have a heightened genetic sensitivity to certain flavours (notably bitterness) while others are blind to them.7 There are also genetic variations in individual appetite, the speed at which we eat and the extent to which people actually enjoy eating.8 We vary in how we chew, how we swallow and how we digest. Some people are born with conditions that make it much harder to eat, such as a delay to the oral-motor system. I had no idea quite how fraught the basic matter of getting food from plate to mouth could be until my third child was born with cleft palate and he and I both struggled at mealtimes. He is now five and new dishes occasionally still provoke tears (usually his). Our relationship with food and weight is additionally affected by epigenetics: our experience in the womb. The ‘thrifty phenotype’ hypothesis of biochemist C. Nicholas Hales and epidemiologist David Barker suggests that being undernourished in utero leaves people with a lifelong propensity for weight gain, an unfair fate to be handed so early.9
The question remains to what extent we are capable of overriding this genetic and epigenetic inheritance and learning new tastes. This riddle can seem impossible to unravel, given that children do not learn to eat under laboratory conditions. As we take our first bites, our parents are supplying us simultaneously with both nature (genes) and nurture (environment conceived in its broadest sense, including everything from cuisine to family dynamics to religion to cutlery and table manners to the ethics of meat to views on whether it’s OK to eat food off the floor if it was only there for five seconds). The two are so intertwined, it’s hard to tell where one starts and the other stops.
In one remarkable experiment, however, a