From Hespos and Baillargeon (2001)
 
 
 

               Tall event         Short event
               (possible)        (impossible)
 

Condition

   Occluder       26.7 sec         34.2 sec
   (behind)

 

 Container        31.7 sec         30.1 sec
    ("in")
 
 

 
 Container         35.2 sec        44.5 sec
 7 months old