Data on infant social evaluation and theory of mind

1. Social Evaluations of 7- and 8-
Month-Old Infants
T.J. Kasperbauer
03/05/12

2. Hamlin, Wynn, and Bloom (2007)

3. Choice Test
6-, 9-, 10-, and 12-month-olds choose the helper.
Hamlin et al., 2007; Wynn, 2008

4. Looking Time Test

5. Looking Time Test
• 9,- 10-, and 12-month-olds look longer when the
climber approaches the hinderer than when it
approaches the helper.
• 6-month-olds look equally to both approaches.
Hamlin et al., 2007; Wynn, 2008
What accounts for the age-difference?

6. Determinants of Social Evaluation
Woodward (1998)
Gergely, Nadasdy, Csibra, & Biro (1995) Premack & Premack (1997)

7. Determinants of Social Evaluation
• Negative judgments of actions and intentions by 6
months (Behne, Carpenter, Call, and Tomasello,
2005)

8. Hamlin and Wynn (2011)

9. Hamlin, Wynn, Bloom, and Mahajan
(2011)

10. Developmental Timeline
• Evaluation (good or bad) of agents by 6 months,
attribution of evaluations to other agents by 9
months (Hamlin et al., 2007; Wynn, 2008).
• Second-order evaluations by 8-month-olds (Hamlin
et al., 2011).

11. Questions
• Will 7- and 8-month-olds perform more like 6-
month-olds or more like 9-month-olds?
• What explains the age difference in the looking time
test?

12. Familiarization

13. Methods (Familiarization)
• 6 familiarization trials (3 helper and 3 hinderer).
• Helper and hinderer events presented in alternating
trials, order counterbalanced across infants.
• Helper and hinderer shapes counterbalanced across
infants.
• 60 seconds for each trial, or until the infant looks
away for at least 2 seconds.

14. Choice Test

15. Methods (Choice Test)
• 4 choice test trials.
• Location of shapes alternates from trial to trial,
counterbalanced across infants.
• Only the first choice is used (per Hamlin et al., 2007).
• Latency to choose is recorded.
• Order of looking time test and choice test is also
counterbalanced across infants.

16. Looking Time Test

17. Methods (Looking Time Test)
• 4 looking time trials.
• Climber approaches either the Helper or the
Hinderer in alternating trials, order counterbalanced
across infants.
• Location of shapes counterbalanced across infants.
• Trial ends when infant looks away for at least 2
seconds.
• Only the first 2 trials are used (per Hamlin et al.,
2007).

18. Participants
• 7-month-olds (11): 6 months, 20 days to 7 months,
15 days.
• 8-month-olds (15): 7 months, 23 days to 8 months,
26 days.
• 10 females and 16 males.

19. Predictions
• Both ages will choose helper.
• No predictions about performance on the
looking time test.

20. Choice Results
7-month-olds: 11/11 chose helper (p < .001)
8-month-olds: 8/15 chose helper (p = .500)
Overall: 19/26 (p = .015)

21. Choice Results
• 7 of 9 7-month-olds made the same choice
twice, p = .09.
• 3 of 12 8-month-olds made the same choice
twice, p = 0.073.

22. Latency to Choose
• 7-month-olds: M = 8.33s, SD = 6.05
• 8-month-olds: M = 8.69s, SD = 6.73
t(23) = -.14, p = .891
• Choose Helper: M = 9.24s, SD = 6.60
• Choose Hinderer: M = 6.29s, SD = 5.12
t(23) = .99, p = .328

23. Looking Time Results
• 7-month-olds:
– Approach Helper: M = 16.63s, SD = 11.12
– Approach Hinderer: M = 17.78s, SD = 8.80
• 8-month-olds:
– Approach Helper: M = 11.72s, SD = 4.26
– Approach Hinderer: M = 10.32s, SD = 6.88
t(9) = -.34, p = .75
t(10) = .72, p = .49

24. Summary
• 7-month-olds prefer the helper.
• No indication of a choice preference in 8-
month-olds.
• Neither age shows a looking time preference.

25. Discussion
What explains the 8-month-olds’ unexpected
choice data?

26. One Possibility: Stimuli Complexity
Why This Seems Unlikely
• Usually such age differences are observed in
younger infants (Moore and Johnson, 2011).
• No explanation for consistency among 7-, 9-,
and 10-month-olds.
• 8-month-olds in Hamlin et al. (2011) made
sophisticated social evaluations.

27. Another Possibility: U-Shaped
Development
• Not enough data to support this.
8-month-old choice data is a bit puzzling.

28. Theory of Mind
• Theory of mind abilities can be seen as early
as 7 months (Kovács, Téglás & Endress, 2010).
• Hamlin et al.’s (2007) task has not been
interpreted as relevant to theory of mind
(Baillargeon, Scott, & He, 2010; Scott &
Baillargeon, 2009).

29. Theory of Mind
SS1: Represents others’ goals and dispositions.
SS2: Represents the extent to which others’
beliefs reflect reality.
(Baillargeon, Scott, and He, 2010; Beate, 2011; Luo & Baillargeon, 2010; Scott &
Baillargeon, 2009)

30. Theory of Mind
Two potential explanations for the age-
difference in the looking time test.
1) Increased social knowledge.
2) Increased theory of mind abilities, specifically
related to SS2.

31. Theory of Mind
Need to compare one’s own evaluation with
that of the climbing shape. This seems more
like SS2.
Results from Hamlin et al. (2011) suggest that 8-
month-olds possess the ability to form
second-order preferences, a theory of mind
ability.

32. Concluding Thoughts
• Although 7- and 8-month-olds performed
more like 6-month-olds in the current
experiment, other research suggests that 8-
month-olds can form sophisticated social
evaluations.
• This shift could be due to Theory of Mind
abilities.