Actually, Tisha, it is a genetic thing they just found out recently. I did 23&Me to find out about my ancestry. What a surprise I found. Not only was I NOT 100% Italian, but I also found out that there is a reason why I think cilantro tastes like soap. Your brother must have the same gene:
“How cilantro tastes to you has a lot to do with your genes,” says SciShow’s Hank Green. He explains that after conducting a few separate studies, scientists were able to pin down most cilantro haters as people with a shared group of olfactory-receptor genes, called OR6A2, that pick up on the smell of aldehyde chemicals. Aldehyde chemicals are found in both cilantro and soap. Uh, yummy?