The Maltese
Despite their small size the Maltese is a comparatively robust little dog who as long as they are well-bred and socialised, are active, friendly, trusting and alert. They bond very closely to their owners and will want to go everywhere with them.
The Yorkshire Terrier
This is an intelligent, lively terrier who is affectionate with their owner but has no idea that they are a small dog! They are fearless, tenacious and protective of their home and their people. They will enjoy games and are constantly on the go. They’ll love nothing more than to be a part of everything their owner does.
From looking at the two breeds that make up the Morkie, the result can only be a small companion dog who will enjoy training and games and loves being in their owner’s presence at all times.
The personality of a Morkie seems to be more consistent when they are first crosses (F1). As a line is successively bred, they can be either bred back to one of the original breeds (and so strengthen either the Maltese or the terrier personalities) or be bred to another Morkie, in which case there is less predictability in temperament (and in-breeding becomes more of a potential issue).
Responsible breeders should be prioritising behaviour as highly as health and so it is important to find a good breeder. A well-bred Morkie should be outgoing and confiden, not nervous, shy or fearful.