Describes behaviors or reactions that seem outdated, coming from our distant past. His atavistic response to the threat was to run away.
Pro Tip 2/3
Emotional Reaction
Used when someone has a gut reaction that's mostly emotional, not based on modern logic. She had an atavistic fear of the storm, like ancient humans might have.
Pro Tip 3/3
Subconscious Drives
Involves instinctual urges or drives we are not consciously aware of. There's an atavistic drive in humans to gather and hoard resources.