Humans have various reasons for valuing some species over others. Researchers asked adults and children of different ages to rank animals from people to worms in the order they would give them a lifesaving drug. In some ways, the children were similar to adults in how they valued the species, but in other ways they were very different. There are subtle shifts in how humans prioritize different species as we develop from childhood into adults.
Herzog, H. 2022. Do kids and adults value animal lives differently Psychology Today Apr 29 https://www.psychologytoday.com/us/blog/animals-and-us/202204/do-kids-and-adults-value-animal-lives-differently