Toddlers Categorically Perceive Emotional Facial Expressions Along a Happy–Sad Continuum
Bibliographic record
Abstract
Adults perceive a continuum of emotional facial expressions categorically rather than continuously. Categorical perception is thought to be adaptive and functional, allowing for inferences that inform behavior. To date, studies have demonstrated categorical perception of some emotional facial expressions in infants. However, a recent study reported that 12-month-olds infants do not perceive facial emotional expressions categorically across a happy-sad continuum. In contrast, toddlers at 3.5 years of age appear to use categorical perception along the happy-sad continuum. Using a novel paradigm that employed the use of a looking-time discrimination task and an explicit identification task, this study measured 26-month-old's identification of faces and ability to discriminate between faces along a happy-sad continuum. Results suggest that 26-month-olds perceive facial expressions categorically along the happy-sad continuum.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.012 | 0.006 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; both teacher heads agree on what is shown here.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".