Final answer:
Children first become certain that a video image of themselves is still 'me' at around 18 months old, as indicated by self-recognition testing such as the mirror test. As they develop cognitively, their self-concept evolves, with significant milestones at ages 2-4 years and further self-identification by age 6.
Step-by-step explanation:
The question addresses the development of self-recognition in children, which is largely a psychological topic. Around age 18 months, children begin showing evidence of self-recognition, as demonstrated by the classic mirror test where toddlers recognize themselves with a red dot of paint on their noses. By ages 24-36 months, children can name and point to themselves in pictures, affirming their self-recognition ability. Furthermore, cognitive milestones continue to develop as children grow. For instance, 2-4 year old children significantly increase their social behavior as they establish a self-concept, which includes difficulty sharing possessions and an understanding of gender roles. As children reach the age of 4, they are more cooperative, can share when asked, and exhibit more autonomy. By the time they are 6 years old, children begin to identify with group memberships and recognize their personality traits.