My parents are both the next to the youngest child in each of their families. Dad was 5th of 6 children and Mom was 10th of 11 children. This made me curious about the average age for each of the people in my direct line when the child I descend from was born. So I made a chart which looks at this for all 4 of my grandparents and their grandparents.
An explanation using the PGF-PGF
1811(YOB of 2nd Great GF)
1854(YOB of Great GF)
1888(YOB of Grandfather)
1930(YOB of my Dad)
The numbers in the age column are the age of that person at the time of their descendant's birth. I included my age at the time of my daughters birth for comparison as well. The average age is listed on the last line of each square within that category. The average of all 16 averages is 33.7 years.
I'm really surprised not to see more of them in the 20-25 range. I tend to think of 20 years as a generation. This can vary a lot depending on ancestors birth order. What you can't tell from this is that my MGM married at 15 and had her first child by age 17. She was 41 when my Mom was born. I just seem to descend from a long line of late in life babies. This is something to consider when trying to decide if that DNA match with whom you share 196 cM is a 2C1R, 2C, Half 1C1R, 1C2R, etc. Are they descending from the youngest child? Were there children from a second marriage? You have to know some things about the family dynamics which is a great argument for researching the sibling lines instead of just sticking to your direct. If you just research your direct it will be very difficult to identify matches connections--even more so than it already is.