General mental abilities have been considered in the differential-psychological plane. It is argued that age peculiarities are the internal conditions, the prerequisites of the development of abilities. Particular meaning of the heterogeny in the age development of mind is presented on the example of children with early mental spurts. The author assumes that individual aspects of abilities do not appeal right away and in a complete form, but only after having proceeded through certain developmental stages. It is shown that understanding of peculiarities of mental abilities in childhood requires proper understanding of relations between the developmental and individual factors.