Infant

Uninformed Adult

Informed Adult

t-value

(df = 14)

p-value

Cohen’s d

t-value

(df = 14)

p-value

Cohen’s d

t-value

(df = 14)

p-value

Cohen’s d

Reach-to-grasp phase

Observer vs. Ball

−3.07

*

1.58

−6.67

*

3.38

−7.16

*

3.65

Observer vs. Rocket

13.53

*

5.14

7.84

*

3.30

5.64

*

2.33

Ball vs. Rocket

20.89

*

7.42

23.78

*

8.05

19.68

*

Lift-to-place phase

Observer vs. Ball

7.03

*

3.34

3.15

*

1.26

2.06

n.s.

0.90

Observer vs. Rocket

1.56

n.s.

0.78

−1.42

n.s.

0.71

−3.82

*

1.83

Ball vs. Rocket

−14.95

*

3.26

−6.73

*

2.56

−8.71

*

3.39