Babies can see the third eye – and we think it’s why they first start to look at faces!

Last night I was doing what I spend most evenings doing at the moment - sitting with my seven-week-old daughter Stella on my lap, just staring into her eyes. For most of the time she avoided my face, looking at the book shelf behind me, as she has done since birth. But then, suddenly, she didn’t something that she hasn’t done much before. She shifted gaze and quite deliberately - even though there was lots else to look at - she looked straight up at my face. Why did she do that?

My PhD supervisor Mark Johnson did some ground-breaking work on this in the 70s and 80s - showing that even newborn babies prefer to look at faces with the features arranged in a human-like configuration. This is important, of course, because we gain so much information – which stimulates future learning- from looking at faces.

But what drives us first to look at faces in the first place? This paper gives a really nice – and simple – explanation for why.

When we’re looking at things close to us we naturally perform vergence eye movements – our eyes don’t point straight forwards in parallel but instead tilt slightly towards each other to focus on things close to us. When we don’t do this – when we’re very tired – or a spaced-out baby – and we stare at something close to us with our eyes staring forwards in parallel then we see in double vision:

When we’re staring unfocused at a face, though, something special happens. Because the distance between my eyes is roughly the same as the distance between my baby’s eyes (a bit bigger I know, but not much): … then when Stella looks at my face her unfocused eyes see my face double, but the left eye from one face image exactly overlaps with the right eye from the other face image, so that the two eye images are superimposed on each other – like this:

This overlap between the two retinal images creates a ‘hot spot’ in our early visual processing, which is what, we think, drives us to stare at faces for long periods.

Try staring at someone’s face quite close – 10cm, as you would a baby – and unfocussing your eyes – the ‘third eye’ just pops out at you.

I love this because it’s a super simple explanation for a behaviour that is SO crucial for so much later development.

And because it means that the third eye – so important in many Eastern traditions, is actually a real thing!

The Images and ideas for this post were taken from this paper:

Wilkinson, N., Paikan, A., Gredebäck, G., Rea, F., & Metta, G. (2014). Staring us in the face? An embodied theory of innate face preference. Developmental Science, 17(6), 809–825. https://doi.org/10.1111/desc.12159