Know thyself

Does a baby know its a baby?

When a baby looks in a mirror does it see what it thinks is another baby, or does a baby recognize itself in the mirror? At what age does consciousness of self emerge?

These are just a few of the questions that we've asked ourselves and discussed with friends. But because of decades of great work by developmental psychologists, there are answers. Humans don't generally interact with mirrors (reaching out to touch the reflection, locking in on reflected eyes) until 4 or 5 months of age. They don't typically recognize themselves until 18 months of age. There is some evidence that other apes also are capable of recognizing themselves in mirrors (as opposed to thinking the reflection is just another animal), however most monkeys don't, nor do other animals (except elephants and dolphins...).


Know thyself, is an aphorism traced back to the Greeks. Knowing how it is that we know about ourselves is something that is really worthwhile knowing. An essay titled "Me" in the mirror., by Tetsuro Matsuzawa of Kyoto University, discusses some of the insights and theory, which i also write about below, that have come out of both developmental and evolutionary studies of our behavior. (You can read Matsuzawa's essay here).

When compared to other primates, humans' cognitive abilities (e.g. face recognition, self recognition) needed for "consciousness" develop much more rapidly inside bodies that still appear immature. There is a fundamental trade-off between an organism's investments in body growth and its investments in brain growth. Biologists generally agree that humans are unique species in the sense that they have undergone heavy selection for "brains" over "guts" and "muscles". Quite possibly the advantages that fire (and cooking), textiles, and stone tools provided allowed reductions in guts and muscles.

Elise impressed me with her cognitive abilities today, which seem rather advanced for her age -- even relative to the average human babies. Elise is now two days short of 3 months, but today, while sitting contently in her sling, I brought her in front of the large mirror we have in our master bath and noticed she was totally entranced by the reflection. I watched her stare at her eye gaze regardless of how i moved her. I then turned her 90 degree to the right to face the other mirror on our medicine cabinet, and, again, she locked in on her eyes and raised her eyebrows - as she often does when something catches her interest. Next, to my complete amazement she reached out and touched the reflection of her finger tip- like when E.T. first makes contact with a human. She continued to touch and feel the "other little baby" which she saw in front of her. This probably lasted for a good 5 minutes before she got bored and didnt want to look or even orient towards the mirror anymore.

I wonder when she'll start using the mirror to interact with herself (which is really one of the first signs of self-recognition)? Will it be relatively early... like soon after 12 months? I'm looking forward to finding out.

Here is a national geographic episode on self-recognition in apes, for anyone who made it through this blog entry and is still kind of curious about self-knowledge and would like to nosce te ipsum.