Babies love mirrors. But research shows that babies typically don’t recognise that it’s THEM they see in the mirror until 18-24 months of age. Researchers test this with the “rouge” or “sticker” test. We surreptitiously place a sticker in the infant’s hair or mark their face with lipstick. Then the baby is placed in front of a mirror to observe their reaction. Prior to 18 months, most babies smile and play with the ‘other baby’ in the mirror.
Closer to 18 months things start to change. Some babies look behind the mirror to see where the ‘other baby’ is hiding. Others are confused by what they see but don’t know why. What your child sees in the mirror evolves as they grow & develop: That’s a mirror (Level 1), there’s a person in it (Level 2), that person is me (Level 3), that person is going to be me forever (Level 4), and everyone else can see it (Level 5).
When an infant actively removes the sticker, we know for sure they understand the ‘other baby’ in the mirror is them! Mirror self-recognition is a pivotal skill, providing the first clear evidence of an understanding of self. An infant’s developing self-awareness means they have begun the representational processes that distinguish between self and other.
The ability to recognise ourselves in a mirror is likely a developmental precursor to ‘theory of mind’ – the ability to attribute mental states to others. It’s the understanding that you and I have different and distinct thoughts, feelings and beliefs. Mirror self-recognition is crucial skill that lays the foundation for so much of what it is to be human.
Without a concept of self & an appreciation that ‘my’-self is different to ‘your’-self, things like language, humour, deception, embarrassment & empathy are impossible. These traits are generally only observed in children in the second year of life – after they’ve stopped trying to play with the baby in the mirror & learned to recognise themselves in the reflection. A concept of self, I am ME and you are YOU, is what allows us to truly connect with one another.
References: Gallup (1998); Nielsen & Dissanyake (2004); Lewis (1995)