Reptile theory was first articulated by David Ball and Don C. Keenan in Reptile: The 2009 Manual of the Plaintiff’s Revolution. It posits that humans have a primitive portion of the brain, similar to reptiles, that is conditioned to pursue safety and survival. On this basis, plaintiffs’ counsel often use reptile theory when presenting personal injury and product liability claims to a jury. They attempt to influence the jury’s decisions by speaking to that “reptilian” portion of the jurors’ brains, painting the defendant as hazardous, dangerous, or a menace to society. Other reptilian tactics are more subtle, though they seek the hallmark emotional “fight or flight” response from jurors, inviting them to decide cases against defendants based on their desire to protect themselves, their loved ones, or the larger community from danger, instead of the evidence presented and the law governing the claims.
Trial judges may not be familiar with reptile theory, which can lead to skepticism. See, e.g., Phillips v. Dull, No. 2:13-cv-384-PMW, 2017 U.S. Dist. LEXIS 90020, at *7 (D. Utah June 12, 2017) (“With regard to arguments based on the ‘reptilian brain,’ the court finds that Defendants have not shown with sufficient particularity what Plaintiff’s counsel should be precluded from saying at trial.”); Dorman v. Anne Arundel Med. Ctr., No. MJG-15-1102, 2018 U.S. Dist. LEXIS 89627, at *17 (D. Md. May 30, 2018) (denying the defendant’s motion because it “is premature and presents vague challenges to Plaintiffs’ style of argument rather than to any evidence that Plaintiffs intend to introduce”). Defendants may have more success by relying on more familiar legal arguments, like those discussed below, when addressing reptilian tactics.