Instinctual (adjective)

1. Relating to or prompted by instinct; natural and unthinking.
2. Relating to or prompted by the innate, inherent nature of something.

Origin:

From latin instinctus ("impulse, drive, instinct"), from instinguere ("to impel, instigat.e")

Examples:

1. The animal's instinctual behavior was to flee when threatened.
2. It was instinctual for him to protect his family when they were in danger.
3. Their instinctual response to the crisis was to band together and help each other.
4. The child's instinctual curiosity led him to explore his surroundings.
5. Her instinctual ability to read people helped her in her work as a therapist.