From the page: But Small has found that it's not all bad news. He points to a continued improvement in complex reasoning skills as we enter middle age. Small suggests that this increase may be due to a process in the brain called "myelination." Myelin is the insulation wrapped around brain cells that increases their conductivity--” the speed with which information travels from brain cell to brain cell. And the myelination doesn't reach its peak until middle age. By this point, says Small, "the neuro-circuits fire more rapidly, as if you're going from dial-up to DSL." Complex reasoning skills improve, and we're able to anticipate problems and reason things out better than when we were young.
And, Small adds, there's another area of improvement as we age: empathy--the ability to understand the emotional point of view of another. Empathy increases as we age.