I was reading this:

http://www.hoagiesgifted.org/d_major_chord.htm

Quote
Social-emotional maturity in intellectually gifted children

Teachers who fear that gifted children may face social and emotional problems as a result of acceleration have often not taken into consideration that intellectually gifted students differ from age-peers of average ability in their emotional maturity almost as much as in their intellectual ability. In children and adolescents emotional maturity is more closely related to mental age than to chronological age. Teachers with a special responsibility for intellectually disabled children are particularly sensitive to the developmental delay which is readily apparent in both their cognitive and affective development; however many teachers are unaware that intellectually gifted children are characterised by advanced affective (as well as cognitive) development.

The most comprehensive longitudinal study ever undertaken in human psychology - the Terman study - is also one of the landmark studies in gifted education. At its commencement, almost 80 years ago, this study contained 1528 children of IQ 135+ (Terman, 1925). The sixth and latest volume of the study, The Gifted Group in Later Maturity, was published only four years ago (Holahan and Sears, 1995). The authors discuss, frankly and comprehensively, the influence of mental age on the subjects� cognitive and affective attitudes and behaviors through childhood and adolescence, and the influence of their high intellectual ability on their relationships, interests and career paths in early, mid and later adulthood.

�Mental age as behavior determinant. Through the school years and into adolescence these children�s interests, attitudes and knowledge developed in correspondence with their mental age rather than with their chronological age. Their academic achievement as measured by tests, their interest and liking for various future occupational careers, their knowledge about and interest in games, their choice of recreational reading materials, and their moral judgments about hypothetical conduct were all characteristic of older non-gifted children whose mental age-range was approximated by this much younger and brighter group. Even the intellectual level of their collections was more mature than that of their chronological age-mates.� (Holahan and Sears, 1995, p. 16)

In both their cognitive and socio-affective development, intellectually gifted children resemble older children much more closely than they resemble their age-peers.

That is about half-way down the page. Right after that is a Linda Silverman example of what it is like to be gifted, with a mental-age of 9, being in a class-room of 6 year olds.

I hope some of these things help...