[iPhantom]

My bad. Well, the conclusion there says differently:

'Yuki’s experience demonstrates that a child growing up with an English-speaking father and a
Japanese-speaking mother in the mostly monolingual environment of Japan is likely to be dominant
in Japanese at the age of two, especially when the child attends a Japanese daycare center full time.'

Anyways, it says he responds to Yuki only when she speaks Japanese.

Quite different from my scenario. Some parents tend to speak 50/50, 2 different languages. There is no way for a child to differentiate this.

By my experience, parents of my little cousin talked sometimes in Greek and sometimes in Albanian language. To each other they talked in Albanian. Outside they talked Greek. The child became totally confused.

My Austrian cousin learnt it my way. He is 5 now and can speak both languages perfectly, and has even an Austrian accent.

Mine is not simply a personal experience, it is a case study on itself... my Greek cousin didn't have dyslexia and the doctors explained it that the parents job on teaching language had screwed and made him anxious on not being able to tell what he wants.