Where there is confusion between trait and state the more general purpose element state should be used even for unchanging characteristics. If you wish to distinguish between characteristics that are generally perceived to be time-bound states and those assumed to be fixed traits, then trait is available for the more static of these. The state element encodes characteristics which are sometimes assumed to change, often at specific times or over a date range, whereas the trait elements are used to record characteristics, such as eye-colour, which are less subject to change. Traits are typically, but not necessarily, independent of the volition or action of the holder.