Why did some of Henry Moore’s large abstract sculptures of the 1960s have fewer obvious human features?

In the 1960s, some of Henry Moore’s large abstract sculptures lost their obvious human features primarily as a consequence of their enormous size.1

While Moore had long been interested in the relationship between the human body and organic forms—such as cliffs, caves, hillsides, and bones—the sheer scale of his works during this decade shifted the viewer's perception. By creating massive objects, the specific human connotations that were present in his earlier, smaller-scale works became less apparent, leading to a more purely abstract aesthetic. This transition allowed Moore to focus on his private interests and explore ideas on a grander scale than he had previously been able to achieve, rather than attempting to tailor his sculptures to the specific requirements of a site.1