Dashiel's actions were driven by curiosity.
Dashiel is 20 months old. His mother tells him that he must not touch the candle that she just lit, and then she turns her back to continue tidying the room. When she turns back around, she sees Dashiel trying to dip his finger in the melted wax under the flame. What best explains Dashiel's behavior?

Curiosity driven action shown by Dashiel

Explanation:        

Curiosity is the feeling which makes a person investigate about any phenomena or happening through experience or learning.It displays interest of person in something.

According to the question, Dashiel's behavior is displaying his curiosity to learn about candle and wax through touching it even though his mother has told him not to do so.He is trying to gain experience and learning because of his interest through attempting to dip finger in wax.