James Byron Dean waxa uu ku dhashay Febraayo 8, 1931, gurigii Seven Gables ee ku yaal geeska wadada 4aad iyo McClure Street ee Marion, Indiana, oo ah ilmaha kaliya ee Mildred Marie (Wilson) iyo Winton Dean. Wuxuu ahaa asal ahaan asal Ingiriis ah, oo leh tiro yar oo Jarmal, Irish, Scottish, iyo Welsh ah. Waxa kale oo uu sheegay in aabihiis uu qayb ahaan ahaa Native American, iyo in hooyadiis ay ka tirsan tahay "silsilad degganeyaal asal ah oo dib loogu laaban karo Mayflower". Lix sano ka dib markii aabihiis ka tagay beeraha si uu u noqdo farsamo yaqaan ilkaha, Dean wuxuu qoyskiisa ugu guuray Santa Monica, California.
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