Thomas Downie, the head of the household in 1841, was born on 2 August 1801 and baptized at Alyth, Perthshire on 5 August 1801, son of James Downie and Jean Moncur, his spouse. His baptism entry shows that his father was a weaver in Dundee and Thomas's birthplace is given as Dundee in the 1851 Census. His parents were married on 20 April 1794 in Blairgowrie, at which time James was a weaver in Green of Blyth.
I have a fair bit of information about Thomas's siblings and their descendants, and on Thomas's own descendants if anyone is interested.