Penny, That is terrible.
What a shock! I remember my parents telling me when I was around 6 or 7. I was a little confused for about 2 minutes, asked a few questions and then moved on.
I can't imagine finding out at 18...and I have dark hair, eyes and skin...I was adopted by English parents so they all have blonde hair and blue eyes!
I don't think it has to do much with your parents generation...my father would have been 74 this year. Your parents made an error in judgement. Some get it right, others don't. It would be a hard call for any parent to know what the right thing to do was.
So do you mean your brother knew for years and was told not to tell you?
Regards JO