David
You are right. I checked my data.
Here is Scotlands People census data which I used to calculate birth dates.
1851 census: Residents at 12 Castle Street, Ceres were.
John Sturrock, age 64, head, linen hand loom weaver, born Ceres.
Anne Sturrock, age 63, wife, born Ceres.
Peter, age 30, son, teacher, born Ceres.
Jane Sturrock, age 27, daughter -in-law, born Perth.
John Sturrock, age 6, grandson, born Merrybank, Perth.
Mary Anne Sturrock, age 3, granddaughter, born Blairgowie.
George Sturrock, age 2, grandson, born Bairgowie.
Barbara Rac Sturrock, age 6 months, granddaughter, born Blairgowie. Could she be Barbara Rae Sturrock?
Christian Butler, girl age 19, house servant.
Even though Sturrock is not my main interest, I have 5 John Sturrocks who are all related. Born abt 1876, d1819-d1894, b abt 1845, b 1847, b abt 1869.
Abt = about (means that the true date is within one year as it was calculated from census age backwards).
I have only one Archibald.
Ian