expressions - What do "attention problems" mean in this context?

I read an abstract from this article:
http://www.ncbi.nlm.nih.gov/pubmed/16180285

Unfortunately I don't have access to the whole content.

In the end of abstract we read that:

However, introducing their non-traditional family into their peer group does not seem to interfere with their psychological well-being. Nonetheless, teachers indicate that children from lesbian families experience more attention problems compared with children from heterosexual households.

What do attention problems mean in this context?

1. Children find it hard to concentrate?


2. Children are in the centre of their peers attention (which might be uncomfortable)?


3. Children ask for teacher's attention too much?

Can we be sure about the selected interpretation?

Answer

Thank you very much for your comments and the answer. As the opinions differ, I think that I cannot draw a definite conclusion about a proper interpretation of the abstract. This is also a satisfactory answer for me.