Re: I wonder...
The half your age +7 was sanctioned by the church in feudal times. The rationale was that males could (and did) marry at 14, and females at 12. These were typically to consolidate political ties between important families. Children could be betrothed at 7 years old. This would mean that two 14 year-olds could get married. It then worked out at 20&17; 30&22; 40&27; 50&32; 60&37; and 70&42. This may well have been because of relatively low life expectancy; likelihood of death in childbirth; and high mortality rates for children, and the need to ensure succession.