You are on a date and by all accounts, it's going well. Midway through dinner, you excuse yourself and head to the bathroom where, to your chagrin, the mirror reveals that you have a streak of sauce on the side of your face. Embarrassed, you wipe it away and rejoin your date.
It's a fairly innocuous scene but it requires an ability that only the most intelligent of animals possess - self-awareness. It's the understanding that you exist as an individual, separate from others. Having it is a vital step to understanding that others are similarly aware and have their own thoughts and desires. As such, it is intimately linked to mental qualities like empathy and selflessness. This may seem obvious to us but even human children only become self-aware in their second year of life.
In the animal kingdom, the skill is even rarer and has only been found ...
