About 20 percent of all children have difficulties that could be connected to behavioral teratogens.
true / false.

True

Explanation:

About 20 percent of all children have difficulties that could be connected to behavioral teratogens, but it is hard to link the teratogens with the difficulties because the relation is not simple or direct.

First, it has to be determined if the brain or emotional problems that the kid has are due to behavioral teratogens or not, which can be hard since there are a lot of factors that can influence teratogens and affect the baby differently.