How could the experiments tell this? Imagine you are a baby. Since you have a short attention span, the experiment will be shorter and loads more fun than most psychology experiments. It was 9) a kind of puppet show; the stage a scene featuring a bright green hill, and the puppets were cut-out shapes with stick on wobbly eyes; a triangle, a square and a circle, each in their own bright colours. What happened next was a short play, as one of the shapes tried to climb the hill, struggling up and falling back down again. 10) , the other two shapes got involved, with either one helping the climber up the hill, by pushing up from behind, or the other hindering the climber, by pushing back from above.