THOSE American pediatricians who are socially oriented may be more familiar with the beautifully expressed observations of 1,000 children born in Newcastle-upon-Tyne, than with the emerging findings of a somewhat less ambitious but comparable attempt to follow the course of 670 children born on an island in the youngest state of their own country. The two studies have in common the fact that they set out to probe the mysteries of nature and nurture by observing children (and families) drawn from a whole community at large rather than groups selected because of condition at birth (such as prematurity) or place of birth (such as a teaching hospital).