This sounds as though it is a bit above me Nicki!!
However, you say "Is it coincidence that the older people tend to be voted out first?"
It depends on what you mean by 'older', because I wouldn't have thought that was particularly true. Dean was the oldest in BB2, but he came 3rd. Craig from BB1 was one of the older ones I think and he won. Similarly, Jonny from BB3 was fairly old and came 2nd and Les from the recent Celeb BB came 2nd. Sandy from BB3 escaped, so we'll never know where he would have come!
The statement is however true for Penny and Lynne who were both voted out first and Stuart was voted out fairly early on.