Alexzander is starting to line things up as well, I think it might just be another way of learning ?? He has also loved putting money into his money box for w hile now, although he has 4 of them he always puts it in the same one!

The only thing I can think of is obsessive compulsive, but as far as I remember he'd be too young for that... I'll check out my psych books & see if I can see anything for you.