Okay, I know this probably isn’t what Gollan has in mind when she writes about weaker links. But, I couldn’t help but relate the story of the French-English bilingual calendars which were accidentally printed with a day missing– Saturday (in English) to be exact. The weak links hypothesis is the idea that because bilinguals need to know more words (words in L1 and L2) they divide their attention and practice between them. Knowing more words leads to less practice with each word. So, the subtle differences in bilinguals’ performance (in comparison to monolinguals) may be due to using words with less frequency. You can read more about this here. Anyway, here the calendar makers had to handle twice as many words (7 vs. 14). In trying to handle 14 (instead of the usual 7) they lost one (oops).
Okay, that’s probably not what happened. But, I think it’s a nice illustration of what happens with bilinguals vs. monolinguals. Bilinguals do need to know all the days of the week in both languages. That’s more to handle, more words vying for attention, which leads to more complexity (and maybe more slips).