Which factors are cited as contributing to domestication around 1959?

• A. Cuteness factor, flightlessness, juvenile look & behavior changes
• B. Increased aggression
• C. Larger size
• D. Longer tails

Answer: (A)

The main idea is that domestication often arises from selecting for tameness, and this targeted selection brings along a cluster of correlated changes—the domestication syndrome. In the fox breeding work that began in 1959, selecting the tamest animals didn’t just produce friendlier behavior; it also led to noticeable changes in appearance and early-life behavior. The animals developed a “cuteness” appeal and retained juvenile features as adults—rounder faces, more expressive eyes, and playfulness—traits tied to neoteny. These juvenile-look traits and the associated behavioral changes are cited as key contributors to domestication because they make animals more approachable and easier to manage for humans, reinforcing the selection for tameness.

Other factors like flightlessness, larger size, or longer tails aren’t the common factors highlighted in that context of domestication research from that period, so they don’t fit as contributing elements in the same way.