Full Idea
In the prototype theory of concepts, a lexical concept has probabilistic structure in that something falls under it if it satisfies a sufficient number of properties encoded by the constituents. It originates in Wittgenstein's 'family resemblance'.
Gist of Idea
The prototype theory is probabilistic, picking something out if it has sufficient of the properties
Source
E Margolis/S Laurence (Concepts [2009], 2.2)
Book Reference
'Stanford Online Encyclopaedia of Philosophy', ed/tr. Stanford University [plato.stanford.edu], p.8
A Reaction
It would seem unlikely to be a matter of the 'number' of properties, and would have to involve some notion of what was essential to the prototype.
Related Idea
Idea 4141 Various games have a 'family resemblance', as their similarities overlap and criss-cross [Wittgenstein]