Persistence of the Intuitive Conception of Living Things in Adolescence

This study investigated whether intuitive, naive conceptions of “living things” based on objects’ mobility (movement = alive) persist into adolescence and affect 10th graders’ accuracy of responses and reaction times during object classification. Most of the 58 students classified the test objects correctly as living/nonliving, yet they demonstrated significantly longer reaction times for classifying plants compared to animals and for classifying dynamic objects compared to static inanimate objects. Findings indicated that, despite prior learning in biology, the intuitive conception of living things persists up to age 15–16 years, affecting related reasoning processes. Consideration of these findings may help educators in their decisions about the nature of examples they use in their classrooms.     

Young Children's Understanding of the Mind-Body Distinction

4 experiments investigated children's understanding of the mind-body distinction. Children of ages 4 and 5 recognized not only the differential modifiability of changeable versus unchangeable human properties and bodily versus mental properties, but also the independence of activities of bodily organs from a person's intention (Experiment 1). When presented 3 types of causal explanations (i.e., intentional, vitalistic, mechanical), 6-year-olds chose most often as most plausible for bodily functions vitalistic explanations (i.e., those ascribing the phenomena to a relevant bodily organ's initiative and effortful engagement in activity); 8-year-olds chose the vitalistic explanations second most often, following mechanical ones (Experiment 2). However, 6-year-olds, as well as 8-year-olds and adults, did not always choose vitalistic explanations over intentional explanations (Experiment 3); whereas they tended to prefer vitalistic explanations for biological phenomena, they predominantly accepted intentional ones for psychological phenomena (Experiment 3A). These results suggest that children as young as 6 years of age have acquired a form of biology as an autonomous domain which is separate from that of psychology.     

Robots and rodents: children's inferences about living and nonliving kinds

This study tests the firm distinction children are said to make between living and nonliving kinds. Three, 4-, and 5-year-old children and adults reasoned about whether items that varied on 3 dimensions (alive, face, behavior) had a range of properties (biological, psychological, perceptual, artifact, novel, proper names). Findings demonstrate that by 4 years of age, children make clear distinctions between prototypical living and nonliving kinds regardless of the property under consideration. Even 3-year-olds distinguish prototypical living and nonliving kinds when asked about biological properties. When reasoning about nonbiological properties for the full range of items, however, even 5-year-olds and adults occasionally rely on facial features. Thus, the living/nonliving distinction may have more narrow consequences than previously acknowledged.     

Preschoolers' Ability to Distinguish Living Kinds as a Function of Regrowth

In order to acquire a theory of biology, children must acquire knowledge about living kinds. Although many studies have shown that preschool children do not accurately classify living kinds and do not use appropriate properties when asked to decide whether something is a living kind, recent work has shown that 3- and 4-year-olds do know something about biological growth. The ability of kinds to heal through regrowth was used in this paper as a measure of children's implicit understanding that plants and animals can be grouped together. In 3 experiments, children were told that animals, plants, and artifacts had been damaged and were asked whether the objects could heal through regorwth and whether a person could mend them. In all studies, children were sensitive to ontological kind, 4-year-olds realized that both plants and animals can regrow but that artifacts must be fixed by human intervention. 3-year-olds were less knowledgeable but did realize that artifacts cannot regrow. Overall, children showed some biological knowledge, implicity grouping plants and animals together and differentiating them from artifacts.     

Nouns Mark Category Relations: Toddlers'' and Preschoolers'' Word-Learning Biases

Recent research suggests that preschool children approach the task of word learning equipped with implicit biases that lead them to prefer some possible meanings over others. The noun-category bias proposes that children favor category relations when interpreting the meaning of novel nouns. In the series of experiments reported here, we develop a stringent test of the noun-category bias and reveal that it is present in children as young as 2 years of age. In each experiment, children participated in a 5-item match-to-sample task. Children were presented with a target item (e.g., a cow) and 4 choices, 2 of which belonged to the same superordinate category as the target (e.g., a fox and a zebra) and 2 of which were thematically related to the target (e.g., milk and a barn). In Experiment 1 we demonstrate that novel nouns prompt preschool children to attend to superordinate-level category relations, even in the presence of multiple thematic alternatives. In Experiment 2, we ascertain that the bias is specific to nouns; novel adjectives do not highlight superordinate category relations. In Experiment 3, we demonstrate the noun-category bias in 2-year-olds. The nature and utility of the noun-category bias are discussed.     

Children''s and Adults'' Models for Predicting Teleological Action: The Development of a Biology-Based Model

Understanding that only living things must act to gain self-beneficial goals is important for developing a theory-like understanding of the living world. This research studied the models that preschoolers, fifth graders, and adults use to guide their predictions of self-beneficial, goal-directed (i.e., teleological) action. Four possible models have been suggested: finalist, complexity based, biology based, and animal based. In Study 1, participants (N = 104) were assigned to one of two conditions that differed in whether a beneficial or neutral object was pictured; they were asked to predict whether animals, plants, machines, and simple artifacts would modify their movement in the direction of that object. Preschoolers' predictions were consistent with an animal-based model, fifth graders' predictions were consistent with biology-based and complexity-based models, and adults' predictions were consistent with a biology-based model. Analysis of both individual response patterns and explanations supported these findings, but also showed that a significant number of preschoolers and fifth graders were finalist, and that very few individual fifth graders followed a complexity-based teleology. In Study 2, participants (N = 84) reported whether the animals, plants, machines, and simple artifacts in Study 1 had psychological capacities. All age groups attributed psychological capacities to animals at levels higher than other domains and at above-chance levels. The evidence from these two studies suggests that preschoolers, unlike fifth graders and adults, predict teleological action for plants and animals on the basis of these entities' inferred psychological capacities.     

Emerging Differentiation of Folkbiology and Folkpsychology: Attributions of Biological and Psychological Properties to Living Things

Research suggests that for adults, "folkpsychology" and "folkbiology" represent distinct conceptual domains for reasoning about living things. However, it is not clear whether these domains are distinct for children; past work suggests that the 2 systems are confused until age 10, and that radical theory change accounts for eventual differentiation. To examine this claim, 16 subjects each at ages 6, 8, and adult were shown pictures of predatory and domestic animals and asked whether each animal displayed a variety of biological properties (e.g., has blood) and psychological properties (e.g., can think, can feel angry). Subjects at all ages showed clearly different attribution patterns for biological versus psychological properties. This dissociation of attribution patterns provides evidence that by kindergarten, notions of folkpsychology and folkbiology are sufficiently differentiated to constitute distinct and independent conceptual domains. This in turn suggests that radical theory change regarding living things either occurs prior to the beginning of formal education, or does not explain the development of folkbiological knowledge.     

Structure mapping and relational language support children's learning of relational categories

Learning relational categories--whose membership is defined not by intrinsic properties but by extrinsic relations with other entities--poses a challenge to young children. The current work showed 3-, 4- to 5-, and 6-year-olds pairs of cards exemplifying familiar relations (e.g., a nest and a bird exemplifying home for) and then tested whether they could extend the relational concept to another category (e.g., choose the barn as a home for a horse). It found that children benefited from (a) hearing a (novel) category name in a relational construction and (b) comparing category members. The youngest group--3-year-olds--learned the category only when given a combination of relational language and a series of comparisons in a progressive alignment sequence.     

As ‘process’ as it can get: students' understanding of biological processes

Students' understanding of biological phenomena are analysed via the ontological categories of processes and matter. The analysis is based on tenth graders' explanations regarding biological phenomena such as photosynthesis, energy resources, temperature regulation and interrelations between living/nonliving worlds. This direction of analysis is an attempt to flow with the more meaningful trend of biological research and thought, that emphasizes the importance and fruitfulness of the process approach. Some implications regarding biology learning and teaching are suggested.     

As Time Goes By: Children''s Early Understanding of Growth in Animals

Beliefs about naturally occurring transformations were examined in children aged 3 to 6 years in 4 experiments. Experiment 1 tested children's understanding that animals (but not artifacts) predictably get larger over time. Experiment 1a examined whether the results obtained in the first experiment could be attributed to an added memory component on the artifact task. Experiment 2 further examined beliefs about the aging of artifacts. In Experiment 3, color and shape (metamorphosis) changes of animals were investigated. At all ages, children appeared to understand that animals get larger and not smaller with age. While older children and adults allowed for rather dramatic changes in the size and shape of animals over the life span if the alternative involved decreasing in size with age, preschool children were less willing to accept these changes. Taken together, the results of these studies suggest that even young preschool children have 2 conceptual insights about natural transformations: that they are lawful and nonrandom, and that they are domain and mechanism specific. Further, children as young as age 3 are able to go beyond the perceptual appearance of animals in making judgments about transformations caused by growth. Implications for children's understanding of personal and species identity are discussed.     

Young children's understanding of random phenomena

2 experiments on the development of the understanding of random phenomena are reported. Of interest was whether children understand the characteristic uncertainty in the physical nature of random phenomena as well as the unpredictability of outcomes. Children were asked, for both a random and a determined phenomenon, whether they knew what its next outcome would be and why. In Experiment 1, 4-, 5-, and 7-year-olds correctly differentiated their responses to the question of outcome predictability; the 2 older groups also mentioned appropriate characteristics of the random mechanism in explaining why they did not know what its outcome would be. Although 3-year-olds did not differentiate the random and determined phenomena, neither did they treat both phenomena as predictable. This latter result is inconsistent with Piaget and Inhelder's characterization of an early stage of development. Experiment 2 was designed to control for the possibility that children in Experiment 1 learned how to respond on the basis of pretest experience with the 2 different phenomena. 5- and 7-year-olds performed at a comparable level to the same-aged children in Experiment 1. Results suggest an earlier understanding of random phenomena than previously has been reported and support results in the literature indicating an early understanding of causality.     

Establishing New Subcategories: The Role of Category Labels and Existing Knowledge

Previous research has revealed that novel nouns highlight category relations at superordinate and basic levels but, paradoxically, make subordinate classification more difficult for preschool children. In Experiment 1, we provide additional evidence that novel nouns put 3-year-old children at a disadvantage in subordinate classification. We suggest that this reflects young children's inclination to label and classify objects at the basic level. In Experiments 2 and 3, we identify 2 circumstances under which 3-year-old children alter their basic level expectation. In Experiment 2, we provide children with specific information to distinguish the relevant subclasses. In Experiment 3, we introduce the novel nouns in conjunction with the familiar basic level labels. Under each of these circumstances, novel nouns do not present an obstacle to subordinate classification. Children's linguistic biases (e.g., the noun-category bias) and their existing knowledge and vocabularies jointly influence early conceptual development.     

Lexical categorization modalities in pre-school children: Influence of perceptual and verbal tasks

This study investigates how categorical organization functions in pre-school children, focusing on the dichotomy between living and nonliving things. The variables of familiarity, frequency of word use and perceptual complexity were controlled. Sixty children aged between 4 years and 5 years 10 months were investigated. Three tasks were used: a naming task; a concepts deconstruction task; and a concepts construction task. Results indicated that age influences: (a) the picture naming and concepts deconstruction task, with older children performing better, and (b) the prevalence of functional features for the inanimate stimuli. These data show that it would be risky to argue that there is a pre-eminence of one concept component without considering the task involved, which is of particular importance in the educational domain.     

Do Lions Have Manes? For Children,Generics Are About Kinds Rather Than Quantities

Generic statements (e.g., “Lions have manes”) make claims about kinds (e.g., lions as a category) and, for adults, are distinct from quantificational statements (e.g., “Most lions have manes”), which make claims about how many individuals have a given property. This article examined whether young children also understand that generics do not depend purely on quantitative information. Five‐year‐olds (n = 36) evaluated pairs of questions expressing properties that were matched in prevalence but varied in whether adults accept them as generically true (e.g., “Do lions have manes?” [true] vs. “Are lions boys?” [false]). Results demonstrated that children evaluate generics based on more than just quantitative information. Data suggest that even young children recognize that generics make claims about kinds.     

The effects of instruction on college nonmajors' conceptions of respiration and photosynthesis

Students in a college nonscience majors' biology course took tests designed to reveal their conceptions of respiration and photosynthesis before and after course instruction. Even though most students had taken at least a full year of biology, serious misconceptions persisted. Most students gave definitions of respiration, photosynthesis, and food which were markedly different from those generally accepted by biologists. These incorrect definitions were associated with more fundamental misunderstandings about how plants and animals function. Most students could not explain how animal cells use either food or oxygen. They understood plants as vaguely analogous to animals, taking in food through their roots instead of mouths. Previous biology instruction seemed neither to improve student performance on the pretest nor to prepare them to master these conceptions during the course. Course instruction did improve student's understanding, but misconceptions persisted for many students. These results raise fundamental questions about the effectiveness of curriculum and instruction in current high school and college biology courses.     

Children''s Awareness of the Biological Implications of Kinship

Preschoolers' thinking about kinship was explored by means of a simple induction task. A target animal was described as possessing a property, and children were asked whether each of 2 other animals shares the property or not. When no information about kinship was given, children in Experiment 1 based their inductions of biological properties on physical similarity. However, when kinship relations were specified, children judged that dissimilar-looking kin share more biological properties than similar-looking but unrelated members of the same species. In Experiment 2, describing the similar animals as socially related did not change the basic pattern of inductions obtained in the first experiment. Moreover, subjects in Experiment 3 did not induce more acquired physical and psychological properties among families than among unrelated animals. The results of Experiments 1 and 2 illustrate one case where young children favor a nonperceptible relation (kinship) over a perceptible one (similarity) as a basis for judgment. The overall pattern of data suggest that young children distinguish to some extent between the biological and social domains.     

Lateralized Neural Responses to Letters and Digits in First Graders

The emergence of visual cortex specialization for culturally acquired characters like letters and digits, both arbitrary shapes related to specific cognitive domains, is yet unclear. Here, 20 young children (6.12 years old) were tested with a frequency-tagging paradigm coupled with electroencephalogram recordings to assess discrimination responses of letters from digits and vice-versa. One category of stimuli (e.g., letters) was periodically inserted (1/5) in streams of the other category (e.g., digits) presented at a fast rate (6 Hz). Results show clear right-lateralized discrimination responses at 6 Hz/5 for digits within letters, and a trend for left-lateralization for letters. These results support an early developmental emergence of ventral occipito-temporal cortex specialization for visual recognition of digits and letters, potentially in relation with relevant coactivated brain networks.     

The nature of preschoolers' concept of living and artificial objects

This study investigated preschoolers' living kinds conceptualization by employing an extensive stimulus set and alternate indices of understanding. Thirty-four 3- to 5-year-olds and 36 adult undergraduates completed 3 testing phases involving 4 object classes: plants, animals, mobile, and immobile artifacts. The phases involved inquiries participants generated, what biological properties they attributed and their assignment of "alive" to the 4 classes. The study also focused on preschoolers' conceptual coherence by examining their responding across indices. Results revealed both competence and confusion in preschoolers' living kinds conceptualization relative to adults'. In addition, demonstrations of coherence across testing situations suggest that the beginnings of an abstract, biologically organized framework for understanding of living and nonliving kinds are in place in the preschool period.     

Understanding Natural Cause: Children''s Explanations of How Objects and Their Properties Originate

An understanding of natural cause includes the realization that events can occur independently of human activity or intentions. It also often entails realizing that causal mechanisms can be nonobservable or nonobvious. The present research investigated to what extent children ages 4-7 have developed a concept of natural cause. Study 1 examined children's understandings of object origins (e.g., how the sun began); Study 2 probed children's causal understandings of object behaviors and properties (e.g., why rabbits hop and have long ears). In both studies, children by age 4 were sensitive to the natural kind-artifact distinction in their explanations. They mentioned human intervention for human-made artifacts but rarely for naturally occurring things. Moreover, subjects at all ages were able to identify specific kinds of natural cause, including intrinsic causes (such as growth) and inborn nature. Finally, subjects understood the link between nonobvious, internal parts and self-generated activity (e.g., that bones are important for the flight of a bird). Altogether, these results suggest that even preschool children realize that natural causes exist. They contradict Piaget's characterization of young children as artificialistic (believing that naturally occurring things are created by people) and as focused on observable properties.