What's the plural form of instinctivity? Here's the word you're looking for.
Answer
The noun instinctivity can be countable or uncountable.
In more general, commonly used, contexts, the plural form will also be instinctivity.
However, in more specific contexts, the plural form can also be instinctivities e.g. in reference to various types of instinctivities
or a collection of instinctivities.
