Notes on the Origins of Human Pointing Gesture Training Study

Danielle Matthews - Department of Psychology, University of Sheffield, UK
Tanya Behne - Department of Developmental Psychology, University of Göttingen, Germany
Elena Lieven - School of Psychological Sciences, University of Manchester, UK
Michael Tomasello - Department of Developmental and Comparative Psychology, Max Planck Institute for Evolutionary Anthropology, Germany

Importance of the pointing gesture in children's social cognition and communication is highlighted.
Previous studies have limited understanding of the ontogenetic origins of pointing.
A training study compared infants with a daily pointing training by mothers against a control group with musical activities.
Participants: 102 infants aged 9-11 months.
Infants tested at the beginning, middle, and end of one month for:
- Declarative pointing ability
- Gaze following ability
Findings:
- Training did not affect index finger pointing ability, which was predicted by prior gaze following ability.
- The frequency of index finger pointing was influenced by gaze following and maternal pointing frequency but not by training.
- Training affected gaze monitoring when pointing and frequency of pointing.
- Suggests that prior social cognitive developments lead to indexical pointing; socialization processes influence gaze monitoring during and frequency of pointing.

Acquiring conventional language is crucial for human cognitive and social development.
Basic elements established through pre-linguistic gesturing, mainly declarative pointing.
Development of pointing is typically around 12 months of age; origins are less understood.
Components of Pointing Gesture:
1. Motoric prerequisites: Ability to extend arm and index finger.
2. Motivational prerequisites: Desire to communicate needs.
3. Social-cognitive prerequisites: Understanding and directing attention.
Theories on Origins of Pointing:
- Spontaneous Onset accounts: Pointing emerges from other developmental achievements.
- Socialization accounts: Emphasize social learning through imitation and adult shaping.
Complexity arises because theories often focus on isolated components of the process.

Great apes demonstrate arm extension; human infants perform ‘open hand’ pointing late in infancy.
Open hand pointing lacks correlation with the comprehension of directive pointing gestures, supporting a notion that index finger pointing is critical.
Human infants extend index fingers non-communicatively earlier, backed by hand structure.
Adaptation of human hand for a pincer grip aids in development of pointing.

Tomasello et al. (2007) propose three motives for early pointing:
1. Imperative: To request objects.
2. Declarative: To share attention with caregivers.
3. Informative or Interrogative: To seek information from caregivers.
Early intent to point may stem from reaching for out-of-reach objects, evolving into ritualized pointing.
Declarative pointing linked to future language skills
Example: Infant 'Carlotta' transitioned from object contemplation to pointing which reveals the communicative intent.

Debate: Is pointing to direct attention or to create behavioral effects?
Possible origins:
1. Spontaneous emergence tied to the ability to follow gaze.

Imitative learning, where infants imitate behavior once they comprehend its function, can also lead to pointing development.

Previous empirical studies mainly correlational.
Study aims to isolate the effects of socialization on pointing onset versus spontaneous development.
Interplay between spontaneous onset and socialization must be elucidated.

102 typically developing infants (58 boys, 44 girls) aged 9, 10, or 11 months participated.
- 15 infants aged 9 months,
- 66 aged 10 months,
- 21 aged 11 months.
Criteria for participation:
- Full-term infants,
- Majority from white, middle-class backgrounds.

Visits: Three visits to university laboratories.
Initial Assignment: Random assignment to a pointing training condition or music condition.
Measurement Tools:
- Test of gaze following.
- Assessing declarations through pointing.
Training Conditions:
- Pointing Condition: Activities included puppet shows, book reading with parent pointing, and commenting on toy actions.
- Music Condition: Involved musical engagement without pointing.

Ability to point not significantly influenced by training but predicted by gaze following scores and age.
Frequency of index finger pointing influenced by maternal pointing frequency and gaze following ability.

Percentage of infants observed pointing increased by visit 3.
Logistic regression models indicated:
- No significant differences by training for index finger pointing; age was a significant predictor.
- Training had a significant positive impact on gaze checking pointing frequency.

Summary of findings:
- Index finger pointing linked to understanding gaze follow.
- Training and maternal pointing influence frequency and gaze monitoring when pointing.
Suggests a base of spontaneous development of pointing prior to socialization influences.

Importance of social development prior to joint attention observed links to pointing.
Training does not expedite index finger pointing but does enhance communicative functions of gestures through mutual gaze checking.

Comprehensive references from various authors including Bates, Tomasello, and more detailing studies on pointing, communication, and social cognition.