© Richard Leeming/Flickr
From the moment they are born, babies are exposed to information that can teach them about who they are. By touching their own face and body, or by kicking and grabbing things, they start to enjoy the influence of their actions on the world. But it is not until children approach their second birthday that they start to develop a sense of self and are able to reflect on themselves from the perspective of somebody else.

One indication of this new objective self-awareness is that children start recognising themselves in a mirror or photograph - something most children do by the age of two. This kind of self-awareness can be assessed scientifically by surreptitiously putting a small mark on a child's forehead, such as by kissing them while wearing lipstick.

The child can't feel the mark so their sense of touch can't alert them to its presence, but they can see it if they look in a mirror. If the child has the capacity to see themselves as another person would, they will reach up to touch the mark when shown a mirror, indicating that they equate the mirror image with their own body.


Toddlers also naturally demonstrate their self-awareness by their ability to use and understand self-referential language such as I, me, you and my. Another example is when they claim something as their own property - the cry of "it's mine" is the origin of many sibling disputes.

The appearance of self-conscious emotions such as embarrassment, pride, guilt and shame also demonstrates that a child is developing self-consciousness. Parents may notice that by the time they are three-years-old, their child is motivated to make amends for wrongdoing, can be proud of their own behavior, or hides when unhappy about something they have done.

Toddlers' ability to think about themselves from the perspective of a second person also marks the start of their acquisition of what's called "self-concept" - stable thoughts and feelings about the self. Between their first and second birthdays, children will be able to produce simple self-descriptions and evaluations such as "I am a good boy", which will become more complex over time.

By the time a child is around eight-years-old, they will have a relatively stable idea of their own personality traits and dispositions, and whether they feel like a valuable and competent person.

Individual differences in personality and feelings of self-worth can influence a child's approach to social situations and academic achievement. Children with positive perceptions of themselves have the best social and academic outcomes, perhaps because they focus on success and aren't deterred by failure.

Parents can help their child develop positive self-esteem by reacting positively to them and their achievements, and helping them to overcome negative events.

Psychologists think parents can also shape children's self-worth right from birth: when they provide a positive response to an infant's actions it provides them with their first experiences of having a positive impact on the world.


Regardless of how children feel about themselves, adding an "idea of me" to their cognitive architecture changes the way they process information. For example, as adults, we remember very few childhood events. One intuitive explanation for this "childhood amnesia" is that until memories can be related to our sense of self, they are very difficult to store and retrieve.

Once a child's sense of self is established, they are more likely to remember information that is related to themselves. This is known as the "self-reference effect" on memory and emerges early on. From at least three-years-old children are more likely to remember objects linked with themselves than those linked with another person.

For example, in one experiment, children between four and six-years-old were asked to sort pictures of shopping items into their own basket, and a shopping basket owned by another person. After the items were sorted, the children were shown a wider selection of shopping items and asked which ones they recognised from the previous game. Children accurately remembered more of the items that they "owned", than items that had been sorted into the other person's basket.

The self-reference effect occurs because items linked with the self - such as "my apple" - attract additional attention and memory support within the brain, ensuring that information of potential use to the self is not lost.

The self reference effect can be used to help children process and learn information, especially as it emerges early in life. So asking children to think about themselves while generating sentences to practice their spelling - such as sentences beginning with the word "I" - can significantly improve their subsequent spelling performance. Putting maths problems in the first-person - for example: "you have four apples more than Tom" - also improves both the speed and accuracy of children's responses.

In summary, selfhood starts at birth, but children don't start expressing an "idea of me" until toddlerhood. Children then start to gather information about themselves and store autobiographical material, starting a life narrative that guides their responses to the world.