Her research found that there is a spot, about 75% down the continuum, where people say they are not people/alive anymore. She also found that people primarily use the eyes to decide if a picture is human and alive.

https://www.blog.theteamw.com/2011/03/31/100-things-you-should-know-about-people-95-people-decide-who-and-what-is-alive-by-the-eyes/