
Yep that's it. I told you to breastfeed!
Okay the exact issue is that soy formula has phytoestrogen (plant based 'hormones' that essentially behave like estrogen). That is why it
could cause more issues for boys than for girls. You are essentially feeding him too much estrogen. . .ahem. . .or so the theory goes.
This is a good answer from the Dr. Sears website and does not assert that one's sex preference is based on the formula he was fed.