Table 5.
Summary table—studies of learning through categorization.
Author(s) and Year | Objectives | Country and sample | Methodology | Key findings for food learning | QA | How children learn | What is learned |
---|---|---|---|---|---|---|---|
Beauchamp and Moran, 1984 | Examine the relationship between frequency and type of experience with sweet substances and sweet preference at birth and 6 months | USA—63 children from birth to 2 years old | Infants' taste preferences were tested at birth and 6 months with sucrose solutions of different concentrations in the following order: plain water, 0.2, 0.6, 0.6, 0.2 M sucrose. At 2 years of age, children were given a series of 3 tests, separated by at least 7 days, in which their acceptance of sweet tastes was evaluated as at birth and 6 months | At 6 months and 2 years, children who had been regularly fed sugar water consumed more of the sucrose solutions (but not more plain water) than children who had not been fed with sugar water. When tested with sucrose in a fruit-flavored drink, prior exposure to sugar water was unrelated to consumption of the sweetened or unsweetened fruit-flavored drink | 8 | Repeated exposure to a sweet taste food; formation of schema that specify a food's usual taste | Expecting and liking a specific food to have a sweet taste |
Brown and Harris, 2012b | Understand how previously liked foods become rejected | UK—Study 1: 312 children aged 6–57 months. Study 2: 89 children aged 12–56 months | Study 1: Parents completed a questionnaire on children's rejection of previously accepted foods. Study 2: Parents completed a questionnaire on children's rejection of previously accepted foods, picky eating and food neophobia | 74% (Study 1) and 49% (Study 2) of parents reported at least 1 occurrence of their child rejecting previously accepted foods (PAF), typically vegetables, mixed foods, fruits, brown foods and foods of mixed color. Study 2: Rejection of PAF was related to pickiness and food neophobia. Findings suggest that changes in form and color of PAF may elicit a neophobic response | 9 | Formation of schemas that specify the food's usual form and color | Rejection of foods that have an unusual appearance |
Cashdan, 1998 | Investigate food habits and aversions in children as potentially adaptive behaviors | USA—129 children from birth to 10 years | Parents (mostly mothers) filled in a questionnaire in which they retrospectively described their child's eating behavior at different ages | Some foods refused by children obscured the food's identity (e.g., foods in sauces, mixed foods, pureed items). 52% of toddlers preferred to eat foods separately rather than mixed; only 3% preferred mixtures of foods | 6 | Formation of schemas that specify the food's usual form and color | Rejection of foods that have an unusual appearance |
Harris and Booth, 1987 | Explore the development of salty food preference and its link with previous exposure to dietary sodium | UK—35 children tested at 6 and 12 months | Infants were tested at 6 and 12 months of age for their preference for salt in familiar foods: unsalted and salted cereal at 6 months and unsalted and salted potatoes at 12 months. The relationship between preference for salted food and the infant's dietary experience was examined | At 6 months a positive correlation was found between preference for the salted test food and the amount of experience the child had with high-sodium foods prior to testing. At 12 months this relationship was affected by the order in which food samples were presented and the infant's familiarity with the tested food | 7 | Repeated exposure to salty foods; formation of schema that specify a food's usual taste | Liking of similar food with added salt |
Macario, 1991 | Explore children's knowledge of the predictive validity of color in determining food category membership | USA—12 children aged between 2.7 and 3.5 years | Children were asked to identify which of a pair of (identical except for color) food or non-food exemplars was the appropriate color. Production and comprehension of color labels was also tested | Children discriminated the appropriately colored items at above chance levels, for both foods and non-foods; younger children named colors less well. Preliminary evidence was found for a relationship between color name knowledge and the ability to recognize a food as inappropriately colored | 7 | Formation of schemas that specify the food's usual color | Usual appearance of familiar foods |
Nguyen, 2007b | Explore children's ability to classify items (including foods) into script and taxonomic categories | USA—14 children aged between 2.2 and 3.0 years (mean age 2.6 years) | Matching task (“which is the same kind of thing?”) with a choice of 2 items to match to target. Targets came from a range of categories, including foods | Children were able to classify and cross-classify foods into taxonomic (e.g., fruits) and script (e.g., breakfast foods) categories | 9 | Formation of taxonomic and script categories that specify the food's type and situations in which it is eaten | Awareness of which foods are appropriate to eat in which combinations or situations |
Rozin et al., 1986 | Explore when children learn what not to eat, i.e., disgusting, dangerous and inappropriate items, and unacceptable combinations of foods | USA—54 children aged between 16 months and 5 years | Children were offered a series of 33 snacks or dinner time foods, inedible, disgusting or dangerous items, or inappropriate combinations of foods to taste; contact with each food was recorded | Children accepted a large number of foods deemed disgusting, dangerous or inappropriate by adults; acceptance of these decreased with age, especially between 16–29 months and 30–42 months; unusual combinations of foods remained acceptable up to 5 years of age | 9 | Formation of schemas for foods and non-food items | Rejection of inappropriate items as non-foods |
Shutts et al., 2009 | Establish whether infants categorize foods by substance rather than shape, as do adults and older children, and therefore whether food constitutes a core knowledge system | USA—Study 2: 40 children aged 9 months. Study 3: 20 children aged 9 months. Studies 4, 5 and 6: 32 children aged 8 months. Study 7: 16 children aged 8 months | Study (2): Infants' looking times were measured toward a display of 2 food items lying on top of each other; when the top item was grasped, either only that item or both items were lifted together. Study (3): as (2), except that two halves of a single food were shown. Studies (4-7): Infants were habituated to an experimenter tasting a food in a specific form and container; test trials showed the habituated stimulus vs. novel food/container/form combinations | Study (2): Infants showed no preference for two foods moving as one or separately; (3): Infants looked longer when single foods broke in two; (4): Infants discriminated changes in food and container; (5): Infants dishabituated equally to changes in food and container; (6 and 7): Infants dishabituated equally to changes in food's color/texture and shape. Overall, there was no evidence that infants treat foods differently to non-foods at 9 months | 11 | Formation of schemas for foods and non-food items | Characteristics of foods that are important to attend to—color and texture, rather than shape or container |
Wertz and Wynn, 2014 | To examine whether infants identify plants and artifacts as a food source after seeing an adult place these in their mouth | USA—Exp 1: 32 infants aged 18 months. Exp 2: 16 infants aged 18–19 months. Exp 3: 16 infants aged 18 months. Exp 4: 32 infants aged 6 months | Exp 1: infants observed experimenters place a dried fruit attached to a plant or an artifact either in their mouth (food-relevant action) or behind their ear (food-irrelevant action). Fruits were then placed on a tray and infants were asked “which foods can you eat?” in the in-mouth condition or “which foods can you use?” in the behind-ear condition. Exp 2: As in Exp 1 but infants were exposed to in-mouth actions of a fruit from a plant or a more familiar artifact. Exp 3: Infants were exposed only to fruits hanging from a plant or from an artifact. Exp 4: In a violation of expectation paradigm, infants were exposed to the in-mouth action for fruits attached to a plant vs. an artifact | After observing an adult place a food from a plant or artifact in their mouth, 6- to 18-month-old infants are more likely to identify the plant as a food source than the artifact | 10 | (a) observational learning of food sources is selective (b) learning about food sources depends on categorization of source as edible | Acceptance of item as edible |