CLPS 0610 Experiments

Hamlin et al. (2007)

Participants: 6- and 10-month-old infants.

Method: Infants watched a puppet show where one puppet helped a climber reach the top of a hill, while another hindered it. They were then offered a choice between the helper and hinderer puppets to measure preference.

Results: Infants significantly preferred the helper puppet, indicating an early sense of social evaluation

Bloom (2000), Ch. 2

Participants: Toddlers (~2–5 years).

Method: Children were exposed to novel words paired with objects while experimenters used social cues (e.g., gaze, pointing) to indicate referential intent. Their word-learning strategies were analyzed based on these cues.

Results: Children relied on intentional cues to infer word meanings, supporting social-pragmatic word learning.

Gelman (2003), pp. 26–43

Participants: Preschoolers (~3–5 years).

Method: Children were asked whether properties (e.g., "has a heart") could change if an animal was altered (e.g., painted to look like another species). Their responses were coded for essentialist reasoning.

Results: Children believed innate traits persisted despite superficial changes, showing early essentialism.

Keil (1989), Ch. 8

Participants: Children (~4–10 years) and adults.

Method: Participants were asked to judge whether transformations (e.g., a raccoon altered to look like a skunk) changed an animal’s identity. Their justifications were analyzed for theory-based reasoning.

Results: Older children increasingly appealed to biological essences, while younger children relied on appearance.

Keil (1989), Ch. 9

Participants: Children (~5–10 years).

Method: Children categorized objects (e.g., "is a bat a bird?") and explained their reasoning. Artifacts vs. natural kinds were compared to test domain-specific reasoning.

Results: Children distinguished natural kinds (innate properties) from artifacts (functional properties) by age 7–8.

Bullock et al. (1982)

Participants: 3- to 5-year-olds.

Method: Children predicted the movement of objects in causal chains (e.g., a ball hitting another ball). Their explanations were coded for understanding of physical causality.

Results: Younger children struggled with indirect causality; understanding improved with age.

Gopnik et al. (2001)

Participants: 15- and 18-month-olds.

Method: Toddlers interacted with a "blicket detector" (a machine that lit up when certain objects were placed on it). Their ability to infer causal relationships from statistical patterns was tested.

Results: 18-month-olds inferred causal rules, demonstrating early scientific reasoning.

Kuhn (2007)

Participants: Children (~6–12 years) and adults.

Method: Participants designed experiments to test hypotheses (e.g., which variables affect pendulum motion). Their control of variables and evidence interpretation were analyzed.

Results: Children improved with age but often conflated evidence and theory without instruction.

Flavell (1999)

Participants: 3- to 5-year-olds.

Method: Children completed false-belief tasks (e.g., predicting where a character would look for a moved object). Their understanding of others’ mental states was assessed.

Results: By age 4, most children passed, showing theory of mind development.

Repacholi & Gopnik (1997)

Participants: 14- and 18-month-olds.

Method: An experimenter expressed disgust for crackers and pleasure for broccoli, then asked the child to share. The child’s food choice was recorded.

Results: 18-month-olds gave the experimenter their preferred food, demonstrating understanding of divergent desires.

Moses (2001)

Participants: 3- to 5-year-olds.

Method: Children performed tasks requiring inhibition (e.g., "Simon Says" or delaying gratification). Their ability to suppress prepotent responses was measured.

Results: Older children showed better inhibitory control, linked to prefrontal cortex development.

Wellman & Liu (2004)

Participants: 3- to 5-year-olds.

Method: Children completed a theory-of-mind scale (e.g., diverse desires, knowledge access, false belief). Their progression through stages was tracked.

Results: False-belief understanding emerged last, following mastery of simpler mental-state concepts.

Sobel (2023)

Participants: 3- to 8-year-olds.

Method: Children explored probabilistic causal systems (e.g., machines that activated inconsistently). Their hypothesis-testing strategies were observed.

Results: Older children used systematic exploration to infer hidden causal rules.

Bauer (2002)

Participants: 6- to 24-month-olds.

Method: Infants imitated actions with novel objects after a delay (deferred imitation). Recall memory was tested by their ability to reproduce sequences.

Results: Recall emerged by 9 months and improved with age.

DeLoache (2000)

Participants: 2.5- to 3-year-olds.

Method: Children searched for a hidden toy in a scale model after seeing it hidden in an analogous real room. Their ability to transfer knowledge across representations was tested.

Results: 3-year-olds succeeded; younger children struggled with dual representation.

Bruck & Ceci (1999)

Participants: 3- to 6-year-olds.

Method: Children were interviewed about past events with suggestive questioning (e.g., "Did the man touch you?"). Their susceptibility to false memories was measured.

Results: Younger children were more likely to incorporate false suggestions into recall.

Carlson & Moses (2001)

Participants: 3- to 5-year-olds.

Method: Children completed tasks requiring inhibition (e.g., whispering when told to shout). Their conflict resolution and delay ability were scored.

Results: Performance improved with age, correlating with executive function measures.

Koenig et al. (2004)

Participants: 3- and 4-year-olds.

Method: Children watched two informants—one accurate, one inaccurate—label objects. They were then asked whom to trust for novel labels.

Results: Children preferred the accurate informant, showing selective trust in learning.

Johnson & Carey (1998)

Participants: 4- to 10-year-olds.

Method: Children were taught false biological facts (e.g., "all fish live in trees") and tested on adherence to these vs. innate intuitions.

Results: Younger children accepted implausible claims, but by age 8, they resisted inconsistent information.

Blake & McAuliffe (2011)

Participants: 3- to 8-year-olds.

Method: Children chose between equal or unequal resource distributions in a "inequity aversion" task. Their reactions to unfairness were recorded.

Results: Rejection of unfairness increased with age, peaking at 6–8 years.

Bonawitz et al. (2011)

Participants: 4- and 5-year-olds.

Method: Children were given a novel toy and either taught its function or allowed free exploration. Their subsequent play was coded for discovery of hidden features.

Results: Children who explored freely discovered more features, showing pedagogical trade-offs.

Legare et al. (2017)

Participants: 4- to 6-year-olds.

Method: Children observed inconsistent causal events (e.g., a machine working unpredictably) and were encouraged to explore. Their explanatory questions and actions were analyzed.

Results: Children engaged in hypothesis-testing behaviors, demonstrating early scientific reasoning.