The red-dot experiment
The famous red-dot experiment has been repeated many times. A baby of 9 months has a red dot put on their nose. They look in the mirror and touch the nose in the mirror, not themselves. By the time they are about 21 months old, ¾ of babies will touch their own nose rather than the mirror. They realise they are looking at themselves.
Why is this significant? It seems as though self-awareness quickly becomes central to children's emotional and social lives.
The second step is self-recognition. Having understood that 'I' exists, then they begin to understand how they are seen in the world with certain qualities and characteristics.
By their first birthday they are beginning to learn that their goals may clash with others. For example grabbing their sister's carefully built tower or breaking something. They realise they can be the focus of others intentions and emotional reactions. If their big sister cries, tells dad and also takes their comfort blanket away in retaliation, the infant becomes sensitive to a range of emotional messages. This self-awareness leads to an understanding of another's perspective. Between their 1st and 2nd birthday they develop more understanding of the goals, feelings and wants of others.
By 2 years of age 'me' consists of knowing they have a name, a gender and other qualities that are specific to them. "I'm a big girl " or " me want more ".