1. in a manner relating to or characteristic of atavism; in a way that shows reversion to an earlier or more primitive form or behavior
Usage: formal; often used in scientific, psychological, or literary contexts

Examples

• The character behaved atavistically, driven by instinct rather than reason.
• Some critics argued that the regime's policies were atavistically authoritarian.
• The artist drew inspiration atavistically from ancient tribal designs.
• His fear of the dark seemed almost atavistically rooted in human evolution.
• The society moved atavistically backward in its treatment of women's rights.