Entity Framework: How to databind to a treeview

Question

I am trying to databind my entity object to a WinForms treeview control but not really having much luck. I have an entity "Person" and I have bound the treeview to the surname of the person which has automatically created a "personBindingSource". In the load event of the form I am calling:

ObjectQuery<Person> orderQuery = context.People;

personBindingSource.DataSource = orderQuery.Execute(MergeOption.AppendOnly);

but on execution my treeview is blank.

Any ideas? There seems to be a bit of info on binding in WPF but nothing on good ol' winforms treeviews.