Like I said, tobacco use has been on the decline for that last 20 years, and they claim these "behavioural problems" have been on the increase for the last 20 years. The only evidence this "study" considers is the tobacco smoke, and they conclude that it is responsible for that increase. I'm not sure what your definition of "solid research" is, but this isn't lining up with mine.
I think one of us misread the research.
I do not recall the research blaming
all
that increase on second hand smoke at all.
This is getting dull and wearying. I'll likely bow out before long. Cheers.