instinctive

/ɪnˈstɪŋktɪv/

The adjective instinctive describes something you do without thinking about it. If you have an instinctive desire to help animals, you might automatically stop your car to pick up every stray dog you see.

Something that is instinctive occurs naturally, the way babies know how to cry and suck as soon as they're born. Adults also have instinctive reflexes — like yawning, or the reflex that makes you kick your leg when the doctor hits your knee with a rubber mallet. Sometimes your instinctive reflexes can save your life — like when the "fight or flight" instinct warns you that danger is present.

Definitions of instinctive

1. adjective

   unthinking; prompted by (or as if by) instinct
   “offering to help was as instinctive as breathing”

   synonyms: natural

   self-generated, spontaneous

   happening or arising without apparent external cause