What is Law of Response by Analogy?

Thorndike’s Law of Response by Analogy is a principle of transfer. How does learning in one situation is transferred to another situation? Thorndike explains 'transfer' by means of 'theory of identical elements'. The theory states that transfer will occur if and only if there are elements in common between the two learning situations. The cat, which has learned to pull the loop in one puzzle box, can show the same or a similar response in another puzzle box, provided that the two boxes share some common identical elements. If the new box would be entirely a different one, transfer will not take place.