Interesting, my interpretation is not at all that the article is referring to "teaching" of babies, merely to the languages to which the babies are exposed.
In my experience (based on observation of a community of immigrants from South Africa in Canada), parents instinctively engage in both English and Afrikaans at home, freely changing between languages (because that is what they are used to), without ever thinking about "teaching the baby another language."
As they grow older, some children seem to gravitate toward either the one or the other language in preference. This seems to be mostly related to a combination of the language primarily used at home (between the parents) and the language primarily used between parents and child.
In this community, I have seen parents making a conscious decision as to whether (or not) to engage in the native language with the child;
For example, parents may choose to limit the use of Afrikaans with the child for fear it will hold back the child's facility with English and thus cause difficulties at school;
Or, for example, parents may choose to engage in Afrikaans anyway (without particular preference for it over English), based on an instinctive feeling (and own experience from South Africa) that children pick up both languages anyway and that it seems to facilitate them in future (eg in learning other languages such as German).
Even in the face of such decisions, the parents still tend to remain in their own patterns at home; for example parents used to Afrikaans as home language might choose to speak primarily English with their children, but still use primarily Afrikaans with each other. The child is still exposed to both, and the babies (as they start speaking) are still using words from both.
In my experience (based on observation of a community of immigrants from South Africa in Canada), parents instinctively engage in both English and Afrikaans at home, freely changing between languages (because that is what they are used to), without ever thinking about "teaching the baby another language."
As they grow older, some children seem to gravitate toward either the one or the other language in preference. This seems to be mostly related to a combination of the language primarily used at home (between the parents) and the language primarily used between parents and child.
In this community, I have seen parents making a conscious decision as to whether (or not) to engage in the native language with the child;
For example, parents may choose to limit the use of Afrikaans with the child for fear it will hold back the child's facility with English and thus cause difficulties at school;
Or, for example, parents may choose to engage in Afrikaans anyway (without particular preference for it over English), based on an instinctive feeling (and own experience from South Africa) that children pick up both languages anyway and that it seems to facilitate them in future (eg in learning other languages such as German).
Even in the face of such decisions, the parents still tend to remain in their own patterns at home; for example parents used to Afrikaans as home language might choose to speak primarily English with their children, but still use primarily Afrikaans with each other. The child is still exposed to both, and the babies (as they start speaking) are still using words from both.