In 1926, at Mt Sinai Hospital in Cleveland, Dr Clara Marie Davis started the most influential experiment ever conducted into the question of human likes and dislikes. As a doctor, Davis saw many children with eating problems – mostly refusal to eat – whose appetites did not match their nutritional needs. She wondered what children’s appetites would look like, freed from the usual pressures of parents and doctors pushing them to eat nutritious foods such as hot cereal and milk, regardless of whether they liked them. Conventional medical wisdom at that time was that children’s particular likes should not be indulged, lest they became ‘faddy’. Dr Davis was not so sure that eating what you liked was automatically a bad thing.
She borrowed a number of infants – some of them orphans from institutions and some the children of teenage mothers and widows – and placed them on a special ‘self-selection diet’ under her medical care. The children – aged from six to eleven months, who had never yet tasted solid food – were offered a selection of whole, natural foods and given free rein, day after day, to eat only what they wished. The full list of foods was:
1 Water
2 Sweet milk
3 Sour (lactic) milk
4 Sea salt
5 Apples
6 Bananas
7 Orange juice
8 Fresh pineapple
9 Peaches
10 Tomatoes
11 Beets
12 Carrots
13 Peas
14 Turnips
15 Cauliflower
16 Cabbage
17 Spinach
18 Potatoes
19 Lettuce
20 Oatmeal
21 Wheat
22 Corn meal
23 Barley
24 Ry-Krisp
25 Beef
26 Lamb
27 Bone marrow
28 Bone jelly
29 Chicken
30 Sweetbreads (offal from the pancreas)
31 Brains
32 Liver
33 Kidneys
34 Fish (haddock)11
At each meal, the infants were offered a selection of around ten foods from this list, all of them mashed, ground up or finely minced. Some, such as bone marrow, beef, peas and carrots, were offered both in cooked and raw form. The selection was laid out in bowls, while nurses sat by, waiting to see what the children would choose. As Davis described it:
The nurse’s orders were to sit quietly by, spoon in hand, and make no motion. When, and only when, the infant reached for or pointed to a dish might she take up a spoonful and, if he opened his mouth for it, put it in. She might not comment on what he took or did not take, point to or in any way attract his attention to any food, or refuse him any for which he reached. He might eat with his fingers or in any way he could without comment or correction of his manners.12
Davis continued this experiment over a period of six years, starting with three babies and building up to fifteen. The results, which have been hotly discussed by doctors ever since, were dramatic. Without any preconceived notions about what foods were suitable for them, the babies showed enthusiasm for everything from bone marrow to turnips. They didn’t realize they weren’t supposed to like beets or offal. All of them tried all of the thirty-four foods, except for two who never attempted lettuce and one who shunned spinach.
Within a few days, Davis noticed, ‘they began to reach eagerly for some and to neglect others, so that definite tastes grew under our eyes.’13 It soon became obvious to her that for the fifteen children, there were ‘fifteen different patterns of taste’. The children made some very odd selections which looked like a ‘dietician’s nightmare’ said Davis. They went on curious ‘food jags’. One day, they might gorge on liver or eat a meal of nothing but bananas, eggs and milk. A boy called Donald showed a rare passion for oranges, cramming in nearly two pounds of them one day.14 In the process of trial and error of finding out what tasted nice, some of the children ‘chewed hopefully’ on plates and spoons, while others grabbed handfuls of pure salt. On trying something new, Davis observed that their faces showed first surprise, then indifference, pleasure or dislike.
However bizarre and unbalanced the children’s likes and dislikes look to our eyes, they served them well. In a 1928 article writing up her findings, Dr Davis included a ‘before’ and ‘after’ photo of one of the children, Abraham G. At eight months, on arriving in her care, he looks a little pale. At twenty months, after a year on the diet, he is cherubic and plump.
When they arrived at the hospital the infants were generally in poor health. Four were seriously underweight; five had rickets. Yet within a few months, all the children were pink-cheeked and optimally nourished. One of the rickets sufferers was offered cod liver oil, which he took the occasional glug of; but the other four managed to get enough vitamin D and calcium to cure their rickets through diet alone. When they suffered colds, they appeared to self-medicate, eating vast amounts of carrots, beets and raw beef. Even though they were given no guidance on what their bodies needed, their ratio of calories averaged at protein 17 per cent, fat 35 per cent and carbohydrate 48 per cent, very much in line with contemporary nutritional science.
Dr Davis created an unprecedented body of information on childish appetites (though it was never fully analysed and, after her death in 1959, all the boxes of raw data were discarded). When Davis took up a new job, the original set-up in Cleveland was moved to Chicago, where she established what amounted to ‘an eating-experiment orphanage’. In all, she logged around 36,000 meals as well as recording changes in height and weight, blood and urine, bowel movements and bone density.15 It is unlikely any scientist will ever get such detailed data again, given the dubious ethics of keeping children locked up in an experimental nursery for so long. The babies stayed on the diet for a minimum of six months and a maximum of four and a half years, during which time they were always at the hospital.
No friends visited and those who were not orphans had little or no contact with their parents. While in the hospital nursery, their lives were subordinated to the needs of the experiment. Such an arrangement would never be allowed now, though Davis evidently cared for the children very much, in her way. She adopted two of them, as a single mother: Abraham G (the plump cherub) and Donald, the passionate orange eater. Many years later, after Donald was dead, his widow recalled that he and Abraham had always been ‘easy to cook for’ and ‘happy to try all kinds of foods’; they remained omnivores all their lives.16
It was such an extraordinary, audacious, borderline-crazy project that Davis attempted: to get to the heart of where children’s food passions come from. It’s just a shame that her experiment proved so easy to misread. Time and again, Davis’s orphanage has been held up as evidence that appetite is mostly genetic and, as a consequence, that the foods children like or dislike are a sure guide to what their bodies need.17 Davis’s food orphanage has been taken as proof that in their natural state, likes and dislikes are genetic and highly individual, like fingerprints: our tastes are a matter of nature, not nurture. What this interpretation fails to take account of is that the biggest thing Dr Davis did was to radically restructure the food environment of the children.
There was a ‘trick’ to the way the experiment was set up, as Clara Davis was the first to point