"childhood is characterized by improvement on tasks of cognitive and motor function, this progress levels off at around age 11 or 12, just prior to adolescence."(You can see the Science Blog coverage of the same study here.)
Our Rabbis teach us something rather interesting. Until the age of 13 (Twelve for girls) a child has only an earthly soul, (sometimes called the 'evil urge') from the age of mitzwoth, thirteen and on, the child receives a Godly soul in addition to the earthly soul. The rest of his or her life is then spent learning to rely on the desires of the Godly soul to elevate the earthly soul.
R' David Zeller of blessed memory, who passed away last thursday (mentioned @ Heichal Negina) wrote in his comments on the Tree of Life:
Judaism and Jewish mysticism in particular tried to warn us about "falling" into seeing everything through duality, by planting the story of the Tree of Knowledge of Good and Evil and the Tree of Life at the beginning of the Torah (the first five books of the Bible). We start out in Paradise (a state of oneness), eat the fruit of the Tree of Knowledge of Opposites, the Tree of Duality, and are out of oneness and paradise. Every child goes through this in his or her early development. But there is almost no education for, no maps to, regaining access to this realm of wholeness, soulness and Godliness.
And those systems that do exist, are mainly descriptions and analysis, linear vehicles - themselves from the Tree of Knowledge - that rarely can transport the seeker to the ever-present dimension of the Tree of Life. The Tree of Knowledge is horizontal, linear, rational, hierarchical, sequential, causal, time and space bound, trapped in the past or sucked into the future. The Tree of Knowledge is the vulnerable, temporal world of the mortal ego/personality/body. The Tree of Life is vertical, holistic, multi-dimensional, simultaneous, overlapping, interpenetrating, beyond time and space, ever present in the here and now moment. The Tree of Life is the safe, protected, womblike timeless world of the immortal soul, life force, essence of all.
Taken together, these three different sources illustrate one beautiful unity. With MRIs and studies we can see the direct effects of what it means to be without a Godly soul, exactly what R' Zeller described. And, from our own experience of what it is to be a teenager, we can see the complexity of the development of a child in the conflict of the Godly and earthly souls. A process that R' Zeller tirelessly worked towards easing.