Early health indicators were not associated with long life. Breastfeeding is not related to long-term health, and personality. In developed areas with good nutrition, breastfeeding can make an only minor difference on overall health. But significant malnutrition, significant prematurity or significant exposure to toxins can translate into severe long-term health threat.
Starting school at an early age has been a mixed story. Some children do well in the school even if they start a year earlier than other kids, while some can get excluded or cannot follow up the courses. Many parents dare to take the risk and try their luck, sending their children who are only five or even younger than five to the school. They are confident that their kids are smart enough to start early. But they might over-simplified this issue: Children who started school at a very young age were more likely to abuse alcohol and less likely to grow up to be very well-adjusted adults. It seems like entering school at a younger age is about something more than academic. The onset of adolescence was not the critical turning point, it was the age at school entry.
Interestingly, the onset of adolescence was not the critical turning point, it was the age at school entry. Terman participants who skipped grades later in their lives did not show higher mortality risk; it was those who entered the school at a younger age became more vulnerable to health problems when they grew up.